San Cristóbal Cañon (Carr. 162/Carr. 725, between Aibonito and Barranquitas) is reportedly the biggest canyon in the Caribbean at 4.5 miles long and 500–800 feet deep. It’s hard to believe this beautiful deep hole in the earth, now filled with verdant green vegetation, was once a garbage dump.
Today it’s a popular site for adventure-seeking outdoorsmen and women who want to get away from it all and witness the canyon’s natural beauty, including a spectacular river, waterfalls, and shoals. The canyon is not accessible without a trained guide [1].
Links:
[1] http://www.moon.com/destinations/puerto-rico/cordillera-central/aibonito-and-barranquitas/recreation