Tulum, meaning fence or wall in Maya, is known as one of the best preserved coastal Maya sites with its unique location overlooking the Caribbean Sea. From the Post Classic Era (1200-1450 AD) it was a major port of call to the neighboring site of Coba. Thought to have been abandoned around the end of the 16th century, Tulum is the 3rd most visited site in the area behind Teotihuacan and Chichen Itza. This is largely due to the fact that it is easily accessible from Cancun and Playa del Carmen, and it is a relatively compact and an easily visited ruin site. There are three main structures of interest: El Castillo (the tower which dominates the area and is perched on the cliff overlooking the Caribbean), The Temple of the Frescoes and The Temple of the Descending God. You can easily cover the site in about 2 hours, and with easy beach access you can take a dip in the cool Caribbean Sea to cool off after you explore.
Located just outside of Tulum, Gran Cenote lives up to its name, it is both amazing and grand! This is a hugely popular spot for cave divers so you are more then likely to see a diver or 2. It is an amazing site to track the divers from the surface with a snorkeling mask as they glide across the bottomless abyss with their dive lights. As they enter the belly of the cave over 9 meters below they light up the caves that would go other wise unnoticed by the oblivious snorkeler. This is by far one of the gems of the area for pure natural beauty, and a must see when visiting the area.