Description: That's what I asked myself, in the words of the famous Gershwin tune, when I first came here. Seriously, I wanted to know WHY I hadn't ever heard of this place after a friend organized a lunch here for a group of mutual friends.

The Mansion on O Street, you see, isn't really a restaurant. It's this amazing upscale boutique hotel/private club that just happens to offer sumptuous buffet meals several times a week, mostly on Sunday and Monday.

There's a "power lunch" buffet every Monday, a champagne brunch from 11 to 2 or a high tea from 3:00-4:30 on Sunday, "Dinner-tini" (dinner buffet with martinis or other libations included) each Monday, and special seasonal events such as dinner buffets for Chinese New Year, Mother's Day, St. Patrick's Day, and so on.

If you drove by the Mansion, you probably wouldn't even notice it. It's housed in a sprawling Victorian row house. (Actually, it's housed in several -- basically, the Mansion was formed by knocking out some adjoining walls to these and cobbling together an eccentric warren of one-of-a-kind boutique suites.)

In fact, calling the Mansion a hotel is rather misleading. It's actually a hybrid blend: a private club, a boutique hotel frequented by visiting dignitaries and celebrities (especially musicians), a museum and art gallery, and, for the likes of me, those open-to-the-public events like the teas, luncheons, and occasional concerts. Clearly, it's a complex set-up. But here's the interesting part: when you visit the Mansion for an event, you can tour it, which is fully half of the fun of going there. (More on that later.)

Thing is, you can't just waltz in. You need to make reservations, plan ahead, maybe organize a group to celebrate a special event, which is how I first came here: a friend was retiring from the Federal Maritime Commission, which is fairly nearby. The "power lunch" I went to the first time cost $25 (it's now $30), and is paid in advance online. (See this link for pesky details on how to book and all the FAQ.) I took the Metro to the closest station, which happens to be Dupont Circle, and after making a few bumbling turns down the wrong street, found the Mansion.

Immediately after going inside and checking in with the young woman standing behind an antique desk in the foyer, I found myself doing what virtually everyone else does: gaping at the buffet tables and furnishings in the opulent wood-paneled rooms on either side. The woman who created The Mansion clearly has a sense of whimsy and wonder: the rooms are full of intricate pieces of art, second-hand-shop type finds, and wonderful crafts. What's surprising, though, is that virtually every piece you see can be purchased if you take a fancy to it. In fact, pick up just about any knick-knack, such as the ones set on every reserved table, and you'll find a little price sticker.

If you've come to meet friends -- and of course that's what you've done -- then as soon as your party is assembled, you'll be shown to a reserved table. Having a meal here feels nothing like eating in a restaurant. Instead, it's as if you've been invited to some wealthy eccentric aunt's for a holiday gathering. There's a pleasant buzz of low-key conversation, much air-kissing and hand-shaking going on, and a palpable feeling of being extremely fortunate to be there that day.

The buffet is set out on several tables. Frankly, it's a little overwhelming. There are hot dishes, cold dishes, plates of hors d'oeuvres perched hither and yon, and plenty of indulgent desserts. Of course, the initial plan of attack is to simply sample anything that looks good -- beef stroganoff, baked lasagna, roast beef, chicken cutlets, chilled salmon, a variety exotic olives and cheeses, artisan breads and rolls, dishes of hot and cold vegetables and lots of salads. Not everything will be to your liking, perhaps, but there will be at least four or five things that you'll want to eat more of than you should. Basically, the menu consists of whatever the chefs whipped up.

The sense of whimsy prevails at the buffet table, too: the central table at dinner was crowned by loaves of Wonder Bread, jars of grape Smucker's jelly, and several jars of Skippy peanut butter (both creamy and chunky, of course). It was very tongue-in-check, set close by the floral centerpiece, the caviar and Stilton cheese.

At lunch, beverages aren't included and need to be ordered, but "Dinnertini" includes whatever you care to order from the bar and as much of it as you like. The second time (or was it third?) that I went to the Mansion with some friends, we were honoring an out-of-town Canadian friend, and decided to have Sunday dinner rather than Monday lunch. Dinner, which is $40, is a relative bargain.

There were perhaps seven or eight other parties dining at the Mansion that evening, no more than thirty or forty people all told, including one group with a British man who looked (and almost certainly was) someone famous -- he was obviously a musician, and looked sort of Eric Clapton-ish. I probably should have recognized him, but I didn't. He had a little entourage. It was fun to speculate who he might be, but of course we confined our curiosity to some discrete glances. (The Mansion zealously guards the privacy of its guests, so even if I had known who he was, I wouldn't say.)

Okay, so you've had a good chat with friends and eaten far too much food. What is left? Dessert, of course. But first, you must do the tour. Or should I say, "the wander." You're free to wander through the labyrinthian rooms of the Mansion. It goes on and on, with several staircases, a little elevator, and lots of narrow passageways. You will almost certainly get lost, which is half the fun, and the next time you come, you might find something you missed the first time. Any room that is occupied will be discretely sealed off -- everything else is fair game.

This part of going to the Mansion simply delights me. Each room -- some positively palatial, others more modest -- is decorated in a distinct style. There are modern rooms and antique-laden ones. Rooms done in flowery chintzes and in rugged knotty pine furniture. An enormous billiard room with a Wurlizer jukebox and a 1950's "American-graffiti" style kitchen and dining room. Many rooms have guitars propped on a chair or set in the corner (look closely -- most have been signed by luminaries such as Bob Dylan). One room, done in white shag carpeting and black lacquer mother-of-pearl furniture, has a John Lennon theme. Go into the splendid bathroom and there's John's holographic image on the floor next to the loo.

One thing is certain: you'll want to spend at least a couple hours at the Mansion. Going there involves far more than merely having a meal -- it's an event. And I, for one, can't wait until the next time I have something to celebrate here. Close