The extraordinary landscape of the terraced salt pools in Maras, that have been providing the valley with salt for years before the Inca period.
Each pool is a polygon shaped approx 4m2 x 30cm deep and is managed by a local family or community member. About 30 days are needed for the water to fully evaporate and the salt to be collected, before the pond keeper opens the water notch again for the water to fill the pond.
Due to a tectonic plate movement, there is an underground water flow of brine (mixture of water and salt) that comes up in a natural spring.
Other impressive sea ponds are the ones in San Francisco (have not visited them yet)