The most-famous (if not quite the tallest) structure at the ancient Maya ruins of Palenque, it’s the Temple of the Inscriptions:

Named for the bountiful art in and on its summit temple, this structure is the final resting place of Pakal the Great, likely the most-important single person in the history of the site.  Sadly, neither the temple nor the crypt beneath it are open to the public any more — the breath of visitors was driving up the structure’s internal humidity levels to the point that they were causing damage.  It’s still an impressive sight from the outside, though — this view is from the south end of the Palace.