Belize
Just a five-hour flight from Los Angeles and a two-hour time difference away, Belize is exotic, yet convenient all at once. Flights are often reasonably priced, and many eco resorts offer affordable and friendly lodging. Of course, you can also splurge at a luxury resort, where private beaches and cabana service await.
More than half of mainland Belize is covered in rainforest, which means there are lush valleys and steep mountainsides to explore. If you look (or listen!) closely at night, you might encounter tapirs, jaguars or black howler monkeys, whose booming howl can be heard from miles away.
While trekking through the verdant landscape, you'll also find lost Mayan cities -- pyramids, palaces and other artifacts built by the ancient people right in the middle of the rainforest. Most of these cities were abandoned more than 1,000 years and rediscovered only recently.
Belize is also home to many caves, where you can examine skeletal remains and ceramics used for ancient Mayan ceremonial purposes, not to mention impressive stalagtites, stalagmites and other wonders of nature. Actun Tunichil Muknal Cave in the Cayo District was deemed the most sacred cave in the world by the National Geographic Society. Its entrance is guarded by a spring-fed pool, so visitors must swim in and wade up a subterranean river for about a half-mile to get to it.
The Belize Tourism Board requires that all tour guides undergo an intensive training and licensing program. So whether you're snorkeling or spelunking, you can rest assured that your guide will not only be highly skilled, but also well versed in Belizean history and culture.