Unlike a traditionally rectangular, chlorine-filled swimming pool, a natural pool is often designed to imitate pools, ponds, or other bodies of water in the wild—they can have irregular shapes, along with rocks, waterfalls, and boulders. Naturally, not every pool built to look like a natural body of water with realistic rocks and boulders is a natural pool.

Unlike most sparkling blue swimming pools, natural swimming pools or ponds (NSPs) are filtered organically rather than using chemicals. This resembles the process by which aquatic plants clean ponds in nature and results in a pool which is not less clean than one with chemically filtered water. The natural pool and its regeneration zone actually create a small ecosystem that changes over time, and animals or insects often are attracted to the zone (but not the pool, thankfully—it doesn’t contain the environment they’re looking for).