Cobá's ruins include the tallest pyramid in Quintana Roo (the second tallest in all the Yucatán) and the thick jungle setting makes you feel like you’re in an Indiana Jones flick. Many of the ruins are yet to be excavated; for now they are mysterious piles of root- and vine-covered rubble. Walk along ancient sacbés (ceremonial limestone avenues or paths between great Maya cities), climb up ancient mounds and ascend Nohoch Mul for a spectacular view of the surrounding jungle.
If walking to the various sites is too taxing, you can rent a bike (M$80) or hire a peditaxi (M$125 to M$180).