Thung lũng, or ravines, are found around the world and make for fascinating sightseeing locations. With a combination of steep walls on either side and water erosion, these steep river valleys carved from rock can be quite breathtaking. The most famous Thung lũng in the U.S. is the Calchaquí in Argentina, while many other popular sites exist in Montana, Iceland, and Brazil. These remarkable landforms can be seen with various shapes, like U-shaped tunnels; and its features, which include deep valleys, rivers and pools, vertical walls, and towering spires of rock, create beautiful scenery. Points of interest often include easy hikes along its length and calm swimming spots on its banks.