Cuevas del Indios (Indian Caves) of Arecibo offers a tidbit of ancient history of a lost people.
An easy-to-find natural wonder, with a simple $2 fee for parking, this you won't want to miss. Bring some sunscreen and your camera.
Begin your hike up sharp and spiky cliff sides (no worries, I was able to do it all in sandals). Work your way up to the top of the cliff and enjoy the fantastic view below. Ocean spray from the massive waves breaking against the side of the rocks will cool you off with a little salty mist. Dare to look over the edge to see a landscape of arches and tunnels, burrowed below your feet.
Climb down into the rocks to find a wonderful—and surprisingly well-preserved—variety of Taino Indian petroglyphs. A small climb down a somewhat sturdy, handmade ladder lands you at the base of the cave with stone carved images surrounding you.
Now is your chance to experience some history. Wander through the smaller tunnels, and listen to the ocean making its way inside the cave with every massive wave crashing outside.