The infiltrative garden or rain garden is a rainwater absorption and filtering system.[1]​ It consists of a depression or hole filled with different layers of filter material (porous stones of different thicknesses), on top of which a garden is planted. This system allows rainwater to flow across impervious surfaces such as pavements, roofs and sidewalks to be absorbed, filtered and returned to the aquifer.[2]​.

The infiltrating garden serves several purposes: it prevents flooding that occurs when water exceeds the drainage capacity of a city; It prevents water from stagnating and accumulating in impermeable depressions and allows it to filter into the subsoil, where it performs the vital function of filling the aquifer.[3]​.