Houses with grassy knolls overhead seem to be cropping up in all corners of the world, particularly for the super wealthy. Sure, the insulating power of greenery makes rooftop lawns an environmental bonus, but there are a host of other reasons these gardens are so en vogue. Often they're the only private greenery available in congested cities—plus, sufficed to say, they're exquisite. Take this Singapore home, above, with gardens on all three floors and about 65 other features that make it prime gawking material. The folks at Guz Architects gave the house twisty wooden staircases and a stone-lined pool one can view from inside the basement, but those are small apples compared to the sloping rooftop and abundance of verdure.
? The bulk of the structure tucked beneath this long bank of lawn is actually not a house at all. Most of it's an epic drive-through art gallery. Architects at KWK Promes gave the art collector owner a "fluid space where the line between living and art could be erased," according to Designboom.
? This covert mansion in Gloucestershire, England sits underneath a ruin of a stone tower. The house sprawls underneath the slight grassy slope, but what's even more interesting are the only floors above ground. The architecture firm De Matos Ryan designed the bedrooms and a game room to be actually inside the tower itself.
? Every bit of this Indonesian home envisioned by Budi Pradono is designed to mesh the industrial and the natural. Yes, there's a rooftop garden, but even more awesome is the use of trees that root in the ground beneath the home and grow through gaps in the ceiling. The foliage peeks out to the grassy rooftop overhead.
? The knoll atop these penthouses in Copenhagen, Denmark serves as an urban sun deck and playground. According to Inhabitat, the roughly 10,700 square feet of rolling grass and play equipment, created by JDS Architects, cost $1.3M to build.