This Mayan city-state is one of the largest and best-preserved ruins of that civilization, and was a dominant force in the Mayan world during the Classic Period (200-900 AD). Located in Guatemala, this place lets you experience your inner Indiana Jones early in the morning or late at night when the tourists go home and it’s just you and the jungle. It is very serene, and that made for one of the best travel memories I have. Be sure to spend the night in the park, as you then really get to see it without the crowds. I particularly enjoyed seeing the sunrise from atop the temples. (Random trivia: The city at the end of Star Wars: A New Hope? Tikal!)