Ah, Casa Anita. Avalonita. Hmmm......well, lemme see if I can remember a good description. What PH19 and you recalled is, of course, correct. And there is a fountain.
Casa Anita:
It's a rambling old castle. Legend has it that when King Arthur pulled Excalibur from the Stone, Merlin took him away for years of tutoring.....and some legends say that Casa Anita is where Arthur studied all those years. I don't really believe that, of course, but it isinteresting.

It's situated on top of the highest knoll in its county; Casa Anita overlooks a tiny hamlet on its west side. During England's feudal years, Dingledongderry (the village; named by my seventeenth-great-grandmother--she was even more eccentric than I am) was the only dwelling on the island that boasted a democratic sort of government and a working sanitation system. Not one person in the village died during the Black Death years later.

But I digress. Back to Casa Anita.

The moat around the perimeter of the castle has been there ever since the castle itself. Every single magical plant resides there (which makes Snape happy; he never has to go out of town for potions supplies). A small colony of merpeople reside there.

hmmmm......anyway.

The actual castle itself has a rather simple layout. Square with four turrets at each corner; a rather massive courtyard in the middle. The courtyard houses my favorite plants. There's a huge rose garden that I love; and I'm contemplating expanding the boxwood maze that takes up the center of the courtyard. Snape tends to the herb part of the greenery. I very rarely ever use those plants anyway, except for the rare occasions that I cook.

The Great Hall of Casa Anita is, as you said, decorated in green and silver. The ceiling is enchanted in much the way the Hogwarts ceiling is enchanted; however, my ceiling does not match the weather outside, but it reflects the weather of my mood. It's a rather useful thing; holding meetings with dignitaries under a growing thunderstorm makes them a lot easier to get along with.

There are over 250 rooms in Casa Anita; they all change locations whenever I'm not looking so it's very interesting trying to make your way to your bedroom when you're half asleep at 2 in the morning. Once I wandered around for nearly two hours one night, searching for my room.

The portraits are under strict order to help anyone who looks lost, though. So that's a great help.

Although the portraits on the second floor east wing do have a tendency to sing their help, so I avoid that wing at all costs. They're not very good singers.

The Great Hall is decorated with marble busts of every nobleman from my family. Making their favorite silly faces, of course. My favorite is Edalbrook the Violent; it's fun seeing the man who terrorized opposing Scottish chieftains making a monkey face.
Also, around the ceilings are huge scrolls of stone parchment. The Skeeters have always been a literary bunch; my twelve-times-great-grandfather actually gave Pepys the idea of starting a journal. Muggles were always slow to think of such things. The throne of the Great Hall is flanked by two golden quills, ten feet high. Interesting thing about these quills is that they work. We use them whenever we hold balls; the quills are used to write festive inscriptions on the stone scrolls overhead.