Oh, I've thought about this myself.. I'm thinking I'd like a summer house near a lake. There's a small peer there, with a wooden rowing boat. I can sit by the lake or go out on the peer, lay down and look down to the bottom. Maybe there's fish there.. you know when you're a kid and enjoying a lazy summer day. There's nice cool breeze to keep everything pleasant, and big, tall trees to climb in. I could climb to the top and have a good look at the landscape and see how the animals are doing, maybe I have a small treehouse up there where I can read..
I like thunderstorms, don't get many of them around here. There could be one rolling by once in a while when the trees and plants feel like it, just to add a little unpredictability to it. Also, after a rain storm the air is so refreshing.
The summer house doesn't look very big from the outside, but if you go in there may be lots of rooms for different purposes and many floors.. with all kinds of state-of-the-art technology and modern furniture. Maybe the house extends underground.. I could have a room underneath a stream or the lake. The ceiling is made of glass, so I could look up though the water, and the sunshine lits up the room.. you have these changing patterns that happen due to the waves on the water.
Of course, the house may also have doorways that leads off to places created for adventure and thrill, like shortcuts to other dimensions. I could go on and on about this..

(I came to think after writing this that I had a period as a kid, where I liked to draw pictures of houses with a zillion rooms and floors, as if there was something magical about it. Maybe I'm simply remembering a place that is already there)