Cobá

After the monkey reserve, we headed back down the road a few
kilometers to the archeological site of Cobá, home to the tallest
Mayan building in the Yucatan. The various temple and building groups
are spread out, but the cheap bike rental makes it easy to wind around
big tour groups and spend time looking rather than walking. I
personally don't have much of a historical frame of reference beyond
"pre-Colombian" to really put the site into context, but the fact that
the top of the temple (142m) is by far the highest thing visible from
one side of the horizon to the other is impressive enough.