In January of 2007, my wife and I visited Belize and Guatemala. Our focus was the ruins of Tikal in northern Guatemala. The unique thing about Tikal is that it is surrounded by dense jungle. We saw a variety of wildlife including monkeys and toucans.
Tikal is actually a National Park and has been designated as a World Heritage site by UNESCO. Tikal is one of the major sites of Mayan civilization, inhabited from the 6th century B.C. to the 10th century A.D. It was the ceremonial center and contains superb temples and palaces, and public squares accessed by means of ramps. Remains of dwellings are scattered throughout the surrounding countryside. You can learn more about Tikal's status here: http://whc.unesco.org/en/list/64. The combination of Belize and Tikal in Guatemala make an ideal one-week trip for a couple in need of a getaway.