Los Tres Ojos (The Three Eyes) is a system of limestone caves on the eastern side of the Ozama River, a few kilometres from the Zona Colonial. The caves contain three lakes — one emerald green, one deep blue-black, and one with clear turquoise water — formed by underground springs in the karst rock. A path leads through the caves and over bridges, with the deepest section accessible by small raft ferry.
The site is genuinely impressive and unlike anything else near the city. It has been a popular excursion from Santo Domingo since at least the early 20th century, and while the tourist infrastructure around it is basic, the caves themselves are well worth the short taxi ride from the colonial district.