Cathedral Cavern

Part of a cave system carved by the world’s second longest underground river, this cave contains ancient petroglyphs left behind by the Taíno Indians, with stylized drawings of everything from spaceships and stars to plants and animals. Dramatic shafts of sunlight illuminate a cathedral-like collection of stalactites and flowstone, and a bat colony inhabits the upper layers of the cave. Adventurous visitors can also make arrangements to go rappelling to depths of 80 to 125 feet.

Old San Juan

Narrow cobblestone streets, colorful colonial buildings, centuries-old fortresses overlooking the Atlantic Ocean, fascinating museums and art galleries, handcrafts on the corners-and everything bathed by a tropical breeze… these are some of the characteristics of legendary Old San Juan. Wear comfortable shoes and light clothing, grab your camera, and get ready to marvel at the perfect marriage of the past and the present via a walking tour or the free trolley.

San Felipe Fort “El Morro”

El Morro, officially known as Fuerte San Felipe del Morro, sits atop a high promontory overlooking the entrance to San Juan Bay, and during the past two centuries has survived countless attached from English, Dutch and American ships. Visit dungeons and hidden passages, stroll through the lawns where soldiers once marched, and gaze over the fort’s 60-foot walls.

Gaming

Those who love to try their luck at casinos will find plenty of them in Puerto Rico. Every day, at almost any hour, the floors are bursting with the energy and hectic movement of tourists and residents alike. The excitement is almost palpable, as players pull for another, whether at the blackjack table or the roulette wheel. Glittering lights, tall ceilings, the inimitable sounds and sights, and the suspense and anticipation make a trip to a casino well worth a visit.

Arecibo Radio Telescope

In the northwest mountains of Puerto Rico, you’ll fine the Arecibo Ionospheric Observatory, the largest of its kind and one of the most important research facilities on earth. In its modern Visitors’ Center you will see how this colossal structure is used to study radio emissions from distant galaxies, quasars, pulsars and many other cosmic sources. The exhibits are interactive and contain valuable information on astronomy and atmospheric science.