This historic area in San Juan exudes old-world charm. Walk along the cobbled streets and past colorful buildings, historic fortresses, and old city walls, some of which date back to the 16th century. You might even chance upon local musicians playing some salsa or jazz tunes. There are also several museums where you can learn more about the history, art, and culture of the area, plus cool cocktail bars and restaurants for a quintessentially Puerto Rican meal. Don't miss all the best sights (and food!) on a walking tour of Old San Juan. – Tripadvisor

Plan a day trip to the only tropical rainforest in the U.S. National Forest System. With 29,000 acres of lush foliage and 25 miles of year-round trails, this is a nature enthusiast’s sanctuary. Attempt to spot elusive wildlife like the Puerto Rican parrot on a rejuvenating hike, soar through the canopies on a zipline, or go horseback riding at Carabalí Rainforest Park. If time permits, visit the Yokahú Observation Tower which has an elevation of 1,575 feet and provides expansive views of the mountains. Sporadic showers are common here—check their website for the latest information about trail statuses and park closures before setting out.

This horseshoe-shaped bay is popular amongst travelers for its clear, calm and shallow waters, and flat white sand. There are food stalls that sell food and drinks, shower facilities, and umbrellas that you can rent. As you walk along the shores, spot Flamenco’s most iconic attraction: the abandoned World War tanks decked in graffiti—a reminder of the US Navy’s occupancy of Culebra. It's a popular day trip spot from San Juan, so expect it to be busier on the weekends. Have your day sorted with a tour of Culebra Island, which typically includes transfers to the island and activities like snorkeling. – Tripadvisor

Discover BACARDI's history through a guided tour, become a rum maestro with the Rum Tasting Tour, or master the Mojito with an interactive Mixology Class!

Watch the world’s brightest bioluminescent bay glow as you paddle a glass-bottomed kayak. Catch a ferry at the port outside the town of Ceiba to reach the quiet island of Vieques off the east coast of Puerto Rico. Vieques’ secluded mangrove bay is beautiful during the day but simply astonishing after sunset. You’ll marvel at the neon blue trail left by microorganisms whenever they are disturbed—just dip your hands in the water and watch the effects. Visit on a dark night (e.g. during a new moon) to ensure peak visibility of the phenomenon. – Tripadvisor

Constructed to defend the San Juan coastline during the 17th and 18th centuries, this dramatic fortress rises 140 feet above the sea on a rocky promontory, and is composed of six huge levels of ramps, barracks, dungeons, turrets, towers and tunnels.

This massive, 27-acre historic fort protecting the eastern gate of old San Juan is considered the largest Spanish fort built in the Americas.

An esplanade greets you as you walk towards the Fort San Felipe del Morro. Surrounded by grassy hills, the stone castle rises majestically from the headland. And while El Morro may be an impressive sight from land, it is a terrifying experience to encounter it head on by sea. And for many attackers, it was the very last thing they saw. This fortress has seen many battles over the centuries, from Sir Francis Drake's attack in 1595 to the 1898 Bombardment of San Juan by the US Navy. In 1539 King Charles I ordered the construction of San Felipe del Morro and other fortifications on the islet of San Juan. Over the years, Spanish, Italian, Irish and American engineers perfected San Juan's defense system, of which el Morro was an essential part. After crossing the stone bridge over the dry moat, you'll walk right into a spacious courtyard that harbor leads you into the castle's more "domestic" areas, such as the kitchen and the chapel. Nevertheless, this is just one of the six levels that form el Morro. On the upper level, you'll find the lighthouse that was restored by the American Coast Guard in 1908. One of the greatest things about this vantage point is that you can see most of San Juan and the bay across from it. Park rangers will guide you throughout the massive fortification, which still houses original cannons, ammunition, and many other objects used by the Spanish militia in Puerto Rico. El Morro was declared a World Heritage Site by UNESCO in 1983, and is currently under the administration of the National Park Service.

Jump off the pier into the turquoise waters at Playa Crash Boat—the calm waters are home to an array of marine life, perfect for snorkeling and diving. Hop on a banana boat for a thrilling ride around the beach, then hit the food trucks around the pier for a pina colada and casual Puerto Rican fare. Later in the day, walk to the lookout to watch the sunset. You'll find picnic tables but no showers or toilet facilities. Both paid and free parking is limited, so be sure to arrive early. Or consider visiting along a tour of west Puerto Rico. – Tripadvisor