The Río Bec Route has one of the largest concentrations of Mayan ruins spanning the states of Quintana Roo and Campeche yet only a small portion have been cleared. Rió Bec is famous for its towers adorned with roof combs resembling latticework, its doorways carved to look like monster mouths, underground passageways that lead to temples atop the pyramids and false narrow staircases lining the front of its towers and pyramids. The ruins located in Quintana Roo are known as the Valley of the Masks and consist of Kohunlich, Dzibanche and Kinichná. 
Kohunlich is a corruption of the name Cohune Ridge (Cohune is a species of fruiting palm common to the area). This ruin is renowned for the giant stucco masks on its principal pyramid, El Edificio de los Mascarones (The Building of the Masks). The 6-foot tall masks – set vertically into the wide staircases – were originally thought to be portraits of the gods but are now considered to be composite sculpture of the rulers of Kohunlich. Recent excavations have turned up 29 individual and multiple burial sites inside a residence building called Temple de Los Viente-Siete Escalones (Temple of the Twenty-Seven Steps). Archaeologists believe there are at least 500 mounds on the site waiting to be explored.

Dzibanché and its sister city Kinichná are thought to have been the most powerful alliance ruling southern Quintana Roo during the Maya Classic Period (AD 300 – 900). At Dzibanché (Place where they write on wood), several carved wooden lintels have been found. At the plaza is the Temple of the Owl, a tomb was discovered atop the temple – the second of its kind in Mexico. Also found here was the famous lintel from Temple IV with eight glyphs dating back to AD 618. It is currently on display in the Chetumal Museum. Nearby Kinichná (House of the Sun) consists of a two-level pyramidal mound split into Acropolis B and Acropolis C, dedicated to the sun god. Here a giant Olmec-style jade figure was found. The area is also filled with orchids, wildflowers, birds and small animals. 

The remainder of the Río Bec ruins beginning with Xpujhil are another 55 Km west of the Valley of the Masks. Open daily 8 AM – 5 PM. Admission: $1, with an extra $3 fee for video cameras. Sundays and holidays are free. Located 40 minutes west of Chetumal on Highway 186. Chetumal is five hours south of Cancun along Highway 307.