Gramercy Park Mansion
I don't mind where my wife and I live right now, (a house full of 12 folks in Harvard Heights), but one thing we don't have is a rotunda. This house, (mansion??), in Gramercy Park not only has one a rotunda but all in all 12 rooms, including three full baths and up to 6 bedrooms, (according to the owner 'back in the day' one would never give the number of bedrooms upstairs as each room could be dedicated to a different use, studies or parlors for instance).
The house is vast, (so big in fact that to capture the rotunda and rest of the house for the first image I had to take five separate photos and stitch them together). As always with the homes in West Adams the staircase is to die for.