Tulum is an ancient Mayan ruin located on the Yucatan Peninsula. On the site are the ruins of a walled port city that sits on the edge of a row of cliff over looking the caribbean sea. It is the third most visited archeological site in Mexico mainly due to its close proximity to the resort city of Cancun, from which leave daily bus tours to the ruins. The site is also famous for the well preserved architecture, beautiful ocean views and snorkeling.