Ader Jamat		Ader Jamat is Veovis's first master work and is recognized by a Korfah V'ja, a ceremony that accepts Veovis's work into the canon of D'ni's greatest books. Only 93 books had been accepted as canon in the history of the Guild, among them the Five Great Classics of D'ni history. Veovis is one of four Guildsmen in the history of D'ni to receive the honor at a young age, among them Ri'Neref, the author of the Book of Earth.
Aridanu		Aridanu is a newer Age found by searchers trying to rebuild D'ni, but it lacked a Maintainer's stamp. However, it turned out to be a beautiful age inhabited by D'ni survivors. Aridanu is a lush Age of beautiful forests and peaceful lakes. The villages are made of stone and wood. It is the family Age of Gadren a Guildsman. Master Tergahn an unrelated Guildsman, also finds refuge on an island in one of its lakes. The lakes are pretty sizable, the foundation bedrock is granite.
Aurack		Aurack is one of the Ages found during Atrus's attempt to rebuild D'ni. Bearing a Maintainer's seal, Atrus and his team are shocked to find evidence on Aurack of a monstrous creature who has killed and eaten one of their search team. It is a hot, humid age with thousands of acres of dense forest and undergrowth. The forest seems to be inhabited by biting insects, birds and unseen creatures rustling in the foliage.
Averone		Averone is the seaside home of Marrim, Carrad, Irras and others who help Atrus and Catherine to rebuild D'ni. The native community there farms, hunts and fishes, and lives in circular lodge houses. Beyond their fields are forests and a river empties into the sea. The community is governed by male elders.
Ae'Gura		Called the Island by the natives of D'ni, Ae'Gura is a column of twisted rock rising from the lake bottom to a height of 350 spans (about 1 mile surface measurement). In the Book of D'ni, the rock is decribed as being split.
Bilaris		Irras, Gavas and Meer find this Age in a house in Jaren District that looks like it has been cleaned from the residue of the plague. gas. It is the family age of a Guildsman from the Guild of Archivists. The main tree covered island is without any trace of human presence except for a path, but the community has dwellings on the smaller islands in the bay, on the far side so they can't be seen from the main island. The other side of the island is surrounded by a large expanse of ocean. It has a cliff of about 30 feet above sea level and white sand beaches below the shelf of rock that makes up the island. Bilaris becomes a source of fruit, fish and fresh water for the growing colony in D'ni.
Cells of Entry		The Cells of Entry reside in a cavern tunneled deep into the earth. The most secure part of D'ni, it was accessed through the Gate of Traitors, 10 spans into the rock. There were 15 prison cells, mostly empty. A cell was a room with a desk and chair behind a solid stone door. The cell merely acted as an entry to the Actually Prison Age which in itself had a secure entry.
Chroma'Agana		This is an age that is used as a place of study and retreat by Atrus and Catherine. It's description is very similar to Myst. There is a cabin and a library, the rocky ground rising in the direction of the library. There are tall Oreadoran oaks through which one can see the sea. The cabin is on one end of the island and the library on the other end. There are workshops and laboratories beyond the library. There is also an observatory where Atrus studies star charts. Before the library, there is a pool of water called the Eye Pool. To the right of the library is a cliff path that leads to a mass of stone called the Anchor Rock. The cliff height is about fifty feet above the sea.
Cleft		The Cleft is a 30 foot deep gash in the side of the dormant volcano that leads to D'ni. It is large enough to host adobe or stone dwellings anchored to its side. It also has ancient steps cut into its side, perhaps because a spring at its bottom provides a constant source of water. The Cleft is home to Anna and Gehn after their escape from D'ni. Later, Anna and her grandson Atrus reside there.
Common Library		The Common Library was the place where citizens of D'ni who were not Guild members could also have access to other ages. The Common Library in the J'Taeri District is similar to the design of the Steward's House. The disturbing thing about the Common Library is the Main Book Room, which appears to be underneath the room where the pedestals with the books are. In it are six skeletons chained to their desks, raising questions of why the D'ni would employ such severe measures of security.
Devokan		This is the new name given to Terahnee and means hope
D'ni		D'ni is an immense cavern that houses an entire civilization of people also called D'ni. The entire D'ni race linked to Earth when their own homeworld was destroyed.
Edarat		The age that Veovis wrote for A'Gaeris, but later is altered by Aitrus to trap and destroy A'Gaeris.
Fifth Age		The Fifth Age is also known as Riven by the natives. It is more advanced culturally than the Thirty-Seventh Age and is home to Catherine. Gehn's personal influence with the natives is considerable and he has been able to enlist some of them to help him with his writing projects.
Gadar		One of the Guild Ages of the Guild of Legislators, the Great Library of Legislation there houses 6,000 years worth of D'ni legislative information, including minutes of Council meetings, hearings, tribunals and committees, as well as private communications between Guild Masters.
Garternay		This is the original home world of both the Terahnee and the D'ni.
Gehallah		A mound two hours from the estate of Ro'Jethhe, it is home to a great amphitheater, and an indoor auditorium known as the Chamber of the Moon. The council of relyimah meets in this chamber and the amphitheater is host to a large gathering of the relyimah.
Gemedet		Gemedet is the special age that Aitrus and Anna wrote together. Aitrus used this age to teach Anna the Art of Writing. The age is named for a D'ni strategy game, and the topography provides Aitrus with the opportunity to study volcanic rock.
Great Shaft		The Great Shaft is built as a quicker way to get to the surface from D'ni. It rises vertically from a cavernous room at it's base. The room is elaborate with marble floors, a mosaic of the city of D'ni in the center surrounded by a blue hoop of mosaic representing the outside world. Black steps wind their way up the shaft to a platform at the top where the final tunnel is excavated to access the surface. The shaft acts as a hub for various tunnels branching off of it. A temporary rail attached to the side of the shaft allows for shuttle transport up and down the well of the shaft. Arches support the openings of the tunnels. Unconfirmed speculation has caused some fans to note similarities between the geographical descriptions of the area around the Great Shaft in sections of the African Sahara. A Richat structure in Mali is reminiscent of the circular stone formation found by Anna and her father. Geographically, another similarity to the book descriptions are the remnants of extinct volcanoes existing in Northern Africa.
Guild House		The Guild House mentioned here is the main seat of government in D'ni. This is where the D'ni Council convenes. A great public square sits outside the main Guild House and on the other side of it, the Great Library.
He'Darra		He'Darra is the infamous location where the P'aarli would bring in the young relyimah boys to train them for service. It is a series of P'aarli quarters, holding pens, and training areas underground. The facility contains the instruments used to force their young charges into submission. In its lowest level are the Book Rooms which hold the link to the P'aarli homeworld.
Inception		The name given to Atrus's first written age, it bears geological and environmental similarities that remind him of the cleft, but the setting is much more lush. His age is well-balanced and stable, and he has mastered the art enough to compose his own phrases. Gehn is highly critical of Atrus's writing, and later in a fit of rage edits out elements that he feels are superfluous.
Irrat		When Anna arrives in D'ni she is taken to a cell on an island in the cavern of Irrat, a cavern adjoining the main cavern of D'ni. Anna describes the view from her window as being bleak with one small red pool acting as a focal point. There the Guild of Linguists is to interrogate her and decipher her language.
J'Taeri District		A respectable district in the Lower City near the harbor, this is where A'Gaeris's headquarters are, and where Aitrus and Veovis are lured to become entangled in a conspiracy against D'ni. The building A'Gaeris headquarters in has the appearance of a respectable merchant's house overlooking the harbor and Kerath's Arch.
Jaren District		The Jaren District is a portion of the city that lies upper northeast section. Aitrus's family home is there overlooking the Park of Ages.
Kerathen District		Like all districts, Kerathen's entry is labeled on the lintel of an arch. This is the district where the D'ni boatmen, innkeepers and traders lived. It's most notorious resident was A'Gaeris.
K'veer		The island mansion of K'veer is the home of Lord Rakeri and his son Veovis. Anna likens it to "a great drill bit poking up from the bottom of the lake."
Kerath's Arch		A large stone arch at the harbor front, Atrus in the Book of Atrus, describes it as being composed of huge, mansion sized blocks of crude undecorated stone. The arch, ten blocks high, is large enough for ships to sail through.
Ko'ah		Guild families had one or more of their own ages. Ko'ah belonged to Aitrus's family. It has three books of commentary. When Atrus returns to D'ni to rebuild, he does remove the book from his ancestral home and Marrim puts it in her knapsack to take it with them.
Lodge		The Lodge is the home of Anna and her father, a building cut of polished stone and lodged into a shelf of rock between a rock wall and the shelf below. A narrow stone bridge, cut by her father, crosses over a 60 foot chasm to a rocky outcrop. The front entrance is a hand carved wooden door, opening to a long low ceilinged room from which extend four other rooms. Three to the right are living quarters, and the room to the left is their laboratory and workshop. A pool of water at the bottom of the chasm, can only be accessed by scaling the rock and provides their only source of water.
Myst		Anna is responsible for writing the age of Myst, although Catherine may have given it some finishing touches, since she seems to be working on it in the prison room on D'ni while Atrus is present. It's an island age where Catherine and Atrus can escape to once Gehn is trapped.
Lower City		D'ni is sectioned into the Upper City and the Lower City. The Lower City is at the base of the Great Cavern. It is home to the common population of D'ni, i.e. people who are not members of the Guilds. The Lower City is the site of the harbor, taverns that are frequented by all D'ni, and the Common Libraries.
Ne'weril District		One of the districts of D'ni, Marrim was not able to find any Ages when she searched that district.
Ni' Ederen		A district in Terahnee that is home to the estate of Ro'Jethhe and its governor Ro'Hadre.
Nidur Gemat		One of six ages belonging to Veovis's family it has hundreds of books of commentary indicating how ancient Veovis's family line is. Aitrus's family didn't have its own age until Kahlis became Grand Master of his Guild. Ko'ah had been written 20 years before for Kahlis. Prior to that they either visited the family ages of friends or the Guild Ages.
Ri'Neref Hall		A building in the Upper City, this is the residence for members of the Guild of Writers named for the first great Writer Ri'Neref. Ri'Neref Hall is actually a complex of interlinked buildings comprising the Hall of the Guild of Writers. Two thousand guildsmen resided there, were educated there and carried on guild business. The guild had its own book rooms and libraries. The Writers Guild was tacitly considered the most prestigious of the 18 guilds. Here, Veovis had his own office as well as living quarters.
Riven		Riven is called the Fifth Age by Gehn. It appears to be one of his more successful experiments, but it too is showing signs of instability. Gehn is eventually trapped on Riven by Atrus and Catherine.
Ro'Derraj		A district in Terahnee.
Ro'Jadre		Ro'Jadre here is used as the place name for the estate of Horen Ro'Jadre, Governor of the Ni'Ederen District. It seems that in Terahnee the names of the estates are the family name.
Ro'Jethhe		Ro'Jetthe here is used as the place name for the estate of Jethhe Ro'Jethhe. It seems that in Terahnee the names of the estates are the family name.
Ro'Tanak		This is the estate in Terahnee that Ymur represents at the relyimah council. Apparently he has taken leadership from another slave called Rafis.
Sedona		One of D'ni's ancient Ages, it is involved in a nova at the time that one of Atrus's team links to it for observation.
Steward's House		A prominent architectural structure at the water front, this is a house where trading of goods took place. The building was constructed of 15 marble pillars supporting a huge dome. This building sustained substantial damage with the fall of D'ni.
Tadjinar		Tadjinar is the city where Anna and her father go for supplies. No other information is known about Jemaranir. The traders are believed to be Moslem because of a reference to Allah.
Terahnee		Terahnee is an Age accessed through the Temple of the Great King. They and the D'ni seem to have a common ancestor, sharing knowledge of the Art of Writing, having a similar language, and sources that cite prophecies known by both cultures. Like D'ni, Terahnee refers to the Age, the language, the civilization and the race of people.
Tre'Merktee		Composed from the D'ni words Tre "at the", and Merktee "poisoned waters", it is an underground desert, The Place of Poisoned Waters. In a D'ni myth about Kerath, the young prince is exiled there.
Te'Negamiris		One of the Burial Ages available to D'ni when they die. The passing of Efanis, who dies after being injured by a cutter, is marked by a ceremony that ends in his body being linked to this age.
Thirty-Seventh Age		An age written by Gehn, populated by a simple indigenous race of people who sustain themselves by fishing, Gehn destabilizes it with his indiscriminate writing. Unable to accept that he has written a faulty age, he eventually destroys the book.
Tomahna		Tomahna is the name of the new age that Atrus writes for the survivors of D'ni. While in Terahnee, he realizes that perhaps its a mistake to rebuild on the ruins of D'ni, so he writes the new age for a new beginning. The D'ni word, tomahn means house.
Upper City		The Upper City of D'ni encompasses the Guild Halls and the districts where the of the ruling class of D'ni resides.
Yakul		One of the many ages belonging to the Guild of Writers and among its most ancient, Yakul is the site of a the first official, private ceremony celebrating Veovis's Korfah V'ja. It was written by the first great Writer of the Guild Ar'tenen