Isolated from its quite idyllic context, this concrete pool pavilion—which is in part submerged beneath the ground—looks more like a Bond villain's lair than an annexed space for swimming at an early-20th-century Art Nouveau villa in Italy. But that's just what it is. Built in the northern city of Alta Brianza by local firm alt_romegialli, La Piscine del Roccolo (or, the Pool of Roccolo) is a low-slung, partially subterranean structure crowned with a planted roof. Inside, white-ceramic mosaic tiles line the floors and several walls, while oak panels separate the indoor pool from a gym and small kitchen. You know, just like in your backyard.