The UK - or to give it its full title, The United Kingdom of Great Britain and Northern Ireland - is a land of contrasts. From the sweeping wilds of the Scottish Highlands and Islands to the picturesque Cotswold villages, and from ancient cities like York to the bustling metropolis of London, the UK has something for everyone. 
Most tourists make time visit the most popular sights of London - the Houses of Parliament with its spectacular towers, (including the clock tower usually known as Big Ben, which is actually the name of the bell inside it,) Buckingham Palace (parts of which are open to the public during the summer months,) the Tower of London, Trafalgar Square, St. Paul's Cathedral, and of course the many world-famous art galleries, museums and theatres. If you are new to London, one of the the best ways to get an instant "feel" of the tourist sites is to go on one of the many tours offered on board special open-topped London buses. These come complete with a commentary - often multilingual - and will point out all the sights as they pass and provide interesting snippets of information to make the tour even more enjoyable. Once you have seen what there is on offer, you can then make your own way round your choice of sites at your leisure - there will be a London underground ("tube") station convenient for wherever you want to go.
Outside of London,
the popular tourist circuit includes the beautiful city of Bath with its sweeping Georgian terraces and Roman Baths, Stratford-upon-Avon, famous as the birthplace of William Shakespeare but a beautiful town in its own right, with half-timbered buildings and thatched cottages, and the picturesque River Avon winding through it; 
York with its spectacular Minster, Roman remains, wonderful Viking museum and narrow cobbled streets full of half-timbered buildings all surrounded by mediaeval walls; and of course the royal castle at Windsor, which looks just as every child will tell you a castle ought to look.
Outside of the towns and cities there is some lovely countryside to explore. The UK abounds in villages and small market towns, all with their own character, and you may be lucky enough to stumble across one or two of the local traditions of the area. 
The landscape ranges from the rolling hills and lowlands of the south and east to the hills and moors of the north and west, with a number of specially-designated National Parks - the Lake District, the Peak District, Dartmoor, Exmoor, Northumberland, the North Yorkshire Moors, the Yorkshire Dales, the Norfolk Broads and the New Forest in England, Snowdonia, the Pembrokeshire Coast and the Brecon Beacons in Wales, and Loch Lomond and the Trossachs in Scotland. These are all areas of outstanding natural beauty or ecological importance - or both - and as such are maintained and protected to preserve them for us all to enjoy, both now and in the future.
Some other websites about places of interest in the UK - these will all take you away from this site; you can return here by using your browser's "back" button.
LAKE DISTRICT | COTSWOLDS | YORKSHIRE DALES
HADRIAN'S WALL | STONEHENGE | WINDSOR CASTLE
PEMBROKESHIRE COAST NATIONAL PARK | SNOWDONIA
EDINBURGH | LOCH NESS | NORTHERN IRELAND
These are not the ONLY websites about these places, or even necessarily the best, but they are all well worth a visit. If you are looking for a one-site tour, try the WINDOW INTO BRITAIN website.
And for the year 2000 only, we have the MILLENNIUM DOME:
Depending on your point of view, the Dome is either the marvel of the age or a monumental Folly in the grand style. Built at Greenwich on the north bank of the Thames, on the zero meridian where the next millennium will officially start on January 1st 2001, it cost £750million and features revolutionary design and cutting-edge technology in its construction. It is over 1 kilometre in circumference, 50 metres high and the dome itself covers 80,000 square metres (20 acres!) Seventy-two kilometres of high strength steel cable supports twelve 100 metre high steel masts. The roof is translucent, self-cleaning fibreglass in two layers as insulation to prevent condensation.
Inside the Dome there are 14 "zones," each dealing with a different aspect of the human experience, and a three times daily show with music by Peter Gabriel which has had excellent reviews - "spectacular" and "outstanding" are the usual descriptions. There is an official website and many unofficial ones : I particularly liked "Igor and Michelle's Review."