15 US Territories.
How many have you visited?

Puerto Rico has three bioluminescent bays, where tiny organisms make the water glow. El Yunque is the only tropical rainforest in the US National Forest System.

Why go: Paddle through water that glows blue with every stroke and walk through 500 years of Spanish colonial history in Old San Juan. Hike to rainforest waterfalls and eat mofongo by the beach.

Cars drive on the left here, a holdover from when Denmark owned the islands. The territory has more than 40 beaches across its three main islands.

Why go: Snorkel at Trunk Bay, often rated one of the world's best beaches. See the ruins of sugar plantations, sail between islands, and swim with sea turtles.

Guam is known as the place "where America's day begins." It has been inhabited for 4,000 years and is home to the Chamorro culture.

Why go: Dive WWII shipwrecks and underwater caves full of tropical fish. Learn about Chamorro traditions and eat kelaguen at a local fiesta.

American Samoa lies south of the equator and has the most traditional Polynesian culture under the US flag.

Why go: Visit one of the least-visited US national parks, which gets fewer than 5,000 visitors a year. Learn about fa'a Samoa (the Samoan way) and hike through volcanic landscapes.

The islands sit near the Mariana Trench, the deepest point on Earth at nearly 36,000 feet. Saipan was the site of one of the bloodiest Pacific battles of WWII.

Why go: Dive underwater caves and see WWII relics across the islands. Swim in the Grotto and learn about Chamorro and Carolinian cultures.

The 1942 Battle of Midway was a turning point of WWII in the Pacific. Today the atoll has the world's largest colony of Laysan albatrosses, with over a million birds nesting here each year.

Why go: See albatrosses cover the island during nesting season and endangered Hawaiian monk seals resting on the beaches. Walk among WWII bunkers in this remote wildlife sanctuary.

Wake is a tiny, remote coral atoll that lies closer to Tokyo than to Honolulu. In WWII, US Marines defended it for 15 days.

Why go: Visit one of the most isolated places on Earth, where few civilians have ever been. See WWII history preserved at this remote Pacific outpost.