The St. Regis Bahia Beach Resort, Puerto RicoRio Grande, Puerto Rico

The El Yunque National Rain Forest, a 28,000 acre preserve, is the only tropical national forest on U.S. soil and was established as a National Park in 1906. More than 100 billion gallons of rain fall here each year, creating a lush forest with plants and animals of incredible variety. Plant life is represented with over 240 species of trees, 50 species of ferns, 20 varieties of wild orchids and a large multitude of flowers. For adventure seekers, a popular attraction is zip lining through the forest.

Puerto Rico's only navigable river, the Espíritu Santo, features a plethora of plant and animal life, including mangroves and many species of birds. This short river is mostly navigated by canoe or very small boat. Staff naturalists guide bird-watching on more than seven miles of nature trails and kayak outings on the 63 acres of canals, ponds and lakes on the resort's grounds. Also nearby is the extraordinary Fajardo Bioluminescent Bay where nighttime kayaking is a favorite adventure.

Old San Juan is a remarkable centuries-old neighborhood spanning seven square blocks. This charming residential and commercial district includes more than 400 carefully restored 16th- and 17th-century Spanish colonial buildings. It has a number of small museums as well as marvelous restored forts. A diverse collection of gourmet restaurants, forts, galleries, shops, jewelry stores, and cafes make it a great place to walk around in and savor the Spanish colonial atmosphere.