The Cobá archaeological zone is a large Maya city spread through jungle, lakes, and causeways. INAH describes it as an important ancient Maya city whose sacbe roads helped it endure after other centres declined; on the ground, that means you pass from group to group along shaded paths rather than standing in one exposed ceremonial core.
Renting a bicycle or hiring a cycle taxi inside the site is the practical move if it is hot. The distances are short on a map but longer under the trees.