This photogenic archaeological site at the northern end of the Sian Ka'an biosphere reserve is underrated. Once known as Chunyaxché, it's now called by its ancient name, Muyil (pronounced moo-hill). It dates from the late preclassic era, when it was connected by road to the sea and served as a port between Cobá and the Mayan centers in Belize and Guatemala. A 15-foot-wide sacbé, built during the postclassic period, extended from the city to the mangrove swamp and was still in use when the Spaniards arrived.
Structures were erected at 400-foot intervals along the white limestone road, almost all of them facing west, but there are only three still standing. At the beginning of the 20th century the ancient stones were used to build a chicle (gum arabic) plantation, which was managed by one of the leaders of the Caste Wars. The most notable site at Muyil today is the remains of the 56-foot Castillo —one of the tallest on the Quintana Roo coast—at the center
of a large acropolis. During excavations of the Castillo, jade figurines representing the goddess Ixchel were found. Recent excavations at Muyil have uncovered some smaller structures.
The ruins stand near the edge of a deep-blue lagoon and are surrounded by almost impenetrable jungle—so be sure to bring insect repellent. You can drive down a dirt road on the side of the ruins to swim or fish in the lagoon. The bird-watching is also exceptional here; come at dawn, before the site officially opens (there's no gate) to make the most of it.