The important Huastec ceremonial center of Tamtoc flourished from AD 700 to 1500. Today it’s one of the few maintained Huastec sites. The cleared part of the expansive site is a plaza with platforms made of river stones. Look for a low bench with two conical altars decorated with faded 1000-year-old frescoes believed to represent Quetzalcóatl, the feathered serpent god. It's 49km from Ciudad Valles, and you'll need to take a taxi or have your own transport to get here.