West of Chetumal, along the border with Guatemala, lie the little-visited but dramatic Río Bec sites, many tucked in dense jungle that harbours diverse birds and beasts, especially in the Calakmul Biosphere Reserve, around the ruins of the same name. The area was once heavily populated by lowland Maya, and linked with the site of Tikal in Guatemala. The largest ruins here, with their long, low buildings, dramatic towers (really elongated, stylized pyramids) and intricate carvings, are easily as impressive as Chichén Itzá, heightened by the jungle setting. The area is accessible either from Campeche or from Chetumal, and you’ll need to have a car or hire a taxi to see many of these sites – but this means you’ll see few other tourists.
The largest town in the area is Francisco Escárcega (usually just called Escárcega), far to the west in Campeche state. It’s a major bus hub, but somewhat dusty and unwelcoming, so most visitors to the sites use the much smaller village of Xpujil, on the border of Campeche and Quintana Roo, as a base for visiting the area. It’s a one-street town straddling Hwy-186, with basic hotels and restaurants, as well as taxi drivers prepared to shuttle visitors around. If you’re in your own car, note that there’s a gas station just east of town.