Maras Salt Ponds
The Maras salt ponds might not be an official "wonder of the world" like Machu Picchu, but having seen both I can personally say that the salt ponds left a bigger impression on me. Maras is a town located in the Sacred Valley, about 25 miles north of Cusco in Peru and it's famous for its salt evaporation ponds, which have been in use since before the Inca Empire.
The ponds are fed by a stream of salty water that flows through a series of channels into thousands of individual ponds set on several terraces. The scale of this place is incredible, and of course impossible to capture in photos. The ponds are set in a valley and there are so many of them they just seem endless.
The ponds function as a collective and everyone in the town has the opportunity to own and work a number of ponds. As the water evaporates, the remaining salt is scraped off in layers. The first layer is pure and fine, the second is pink and rocky and the third has traces of soil and minerals and is used mostly for medicinal purposes.
We took a half day tour booked through our hotel of the Sacred Valley that included Maras, but I think it's relatively easy to get to on your own. I'm not usually a group tour kind of person, but having an English-speaking guide was nice. I first saw Maras on Instagram—not surprising because it's infinitely photogenic—but it's definitely one of those places that has to been seen in real life to even begin to be believed.