Castillo de San Cristóbal

#1 Bioluminescent Mosquito Bay (Vieques) This south Vieques beach might not sound like much, but it's one of travelers' favorite experiences in Puerto Rico. During the day, Bioluminescent Mosquito Bay is your stereotypical Caribbean ... Read more » Todd Van Hoosear / Flickr

#2 El Morro (Fuerte San Felipe del Morro) El Morro juts out of San Juan harbor beckoning to cruise ships just as it used to deter sea attacks. The structure is a hulking six-story fortress built between 1539 ... Read more » dranzi / iStockphoto.com

#3 Flamenco Beach On the island of Culebra — which sits about 20 miles east of Puerto Rico— visitors will find a beach perfect for families, snorkelers and those looking for a remote spot ... Read more » ARENA Creative / Shutterstock

#4 Sun Bay (Vieques) Mosquito Bay is popular in the evenings, but the island of Vieques' daytime beachcombers like the chalky sands and serene vantage point of southwestern Sun Bay. It's also the ... Read more » MsDivinity / Flickr

#5 El Yunque National Rainforest Sometimes referred to as the Caribbean National Forest, the El Yunque National Rainforest, or simply El Yunque, this lush expanse is the only tropical forest in the U.S. National ... Read more » epslight / Getty Images

#6 Castillo de San Cristobal Fort San Cristóbal's 27 acres were built to protect the city of Old San Juan from land attacks. It doesn't receive as many visitors, or as much adoration ... Read more » Terraxplorer / Getty Images

#7 Calle del Cristo Outlet shoppers should come to Old San Juan prepared to let go of a few dollars. The city's Calle del Cristo is a haven of restaurants, art galleries and ... Read more » Erin Shields / USN&WR

#8 Condado Beach If you're staying in San Juan there's a good chance you'll never venture farther than Condado Beach. For many sun-lovers, that's just fine. Condado is framed ... Read more » dennisvdw / Getty Images

#9 Museo de Arte de Ponce Following an extensive renovation, Museo de Arte de Ponce reopened in 2010 boasting a bigger space and a larger art collection. Today, the museum houses more than 4,500 works ... Read more » Daniel Lobo / Flickr

#10 Carolina Beach (Balneario de Carolina) Located near the Isla Verde resort area in greater San Juan, lengthy Carolina Beach is a popular public beach among both visitors and locals. Families especially love its white sand ... Read more » runneralan2004 / Flickr

#11 Parque de las Cavernas del Rio Camuy Most travelers say the same thing about the Parque de las Cavernas del Río Camuy: Loved the caverns, didn't care so much for the tour. Too bad it's ... Read more » Jason Sturner / Flickr

#12 Luquillo Beach (Balneario de Luquillo) The resort beaches along Condado or Isla Verde are beautiful, but if you tire of the same old scenery, take a 30-minute drive east along Route 3 to Luquillo Beach ... Read more » arenacreative / Getty Images