Lodged between the Westin Lagunamar and the Park Royal Pirámides, Yamil Lu’um (Blvd. Kukulcán Km. 12.5, free) consists of two small temples that were built between A.D. 1200 and 1550: the Templo del Alacrán (Temple of the Scorpion), owing its name to the remains of a scorpion sculpture on one of its walls, and the Templo de la Huella (Temple of the Handprint), so named because of a handprint found in the stucco.
Unfortunately, neither the scorpion sculpture nor the handprint is visible these days. The ruins are well above the beach on Cancún’s highest point, suggesting that the two small temples were used as watchtowers, lighthouses, and navigational aids.
To see the ruins, go to the concierge at either the Westin or the Park Royal Pirámides and ask if you can walk through to the site. If you’re refused, head to Playa Marlín [1]—at the very least, you can see it from afar.
Links:
[1] http://www.moon.com/destinations/cancun-the-yucatan/cancun-cozumel-and-the-riviera-maya/cancun/sights/zona-hotelera-beaches