Mexico's Yucatán: Cenotes, Maya Ruins, and the Caribbean Coast

The Yucatán Peninsula is a flat limestone shelf that juts into the Gulf of Mexico and the Caribbean, and its geology — porous limestone that absorbs rainfall and channels it into an underground river system — has produced one of the world's most extraordinary natural features: the cenotes. These sinkholes, formed when the limestone roof of an underground cave collapses, expose the crystal-clear groundwater below and were sacred to the Maya, who used them for ritual offerings and as a source of fresh water.

The cenotes of the Yucatán range from open pools to underground caverns accessible only by diving, and the experience of swimming in one — the water so clear you can see 30 metres, the stalactites hanging from the cave ceiling, the light filtering through the opening above — is one of the finest in Mexico. The cenotes near Valladolid (Cenote Zací, Cenote Samulá) and the Ruta de los Cenotes west of Puerto Morelos are the most accessible and the most beautiful.

Chichén Itzá is the most famous Maya ruin in Mexico and one of the New Seven Wonders of the World — a complex of temples, ball courts, and observatories built between the 9th and 12th centuries CE. The El Castillo pyramid, which casts a shadow in the shape of a serpent descending the staircase at the spring and autumn equinoxes, is the most photographed structure in Mexico. The site is best visited at opening time (8am) before the tour buses arrive from Cancún.

Tulum, on the Caribbean coast, is the only Maya ruin built directly above the sea — a walled city on a cliff above a turquoise bay, with a small beach below where sea turtles nest. The ruins are less architecturally impressive than Chichén Itzá but the setting is incomparable, and the combination of the ruins, the beach, and the reef just offshore makes Tulum one of the finest half-day excursions in the Yucatán.

The Sian Ka'an Biosphere Reserve, south of Tulum, is a UNESCO World Heritage Site of mangroves, lagoons, and coral reef that covers 5,000 square kilometres of the Caribbean coast. The boat tours through the reserve's canals — floating on the current through channels lined with mangroves, past herons, crocodiles, and manatees — are one of the finest wildlife experiences in Mexico.

Mérida, the capital of Yucatán state, is one of the finest colonial cities in Mexico — a place of pastel-coloured mansions, Sunday concerts in the main plaza, and a food culture built around the distinctive flavours of Yucatecan cuisine: cochinita pibil (slow-roasted pork marinated in achiote), sopa de lima (lime soup with chicken and tortilla strips), and the papadzules (tortillas filled with hard-boiled eggs and covered in pumpkin seed sauce) that are unlike anything else in Mexican cooking.

The best time to visit the Yucatán is from November to April, during the dry season, when the weather is warm and sunny and the humidity is manageable. The hurricane season (June to November) brings the risk of storms, particularly in September and October, and the summer months are hot and humid. The spring equinox (around March 21) is the best time to see the serpent shadow at Chichén Itzá, but the crowds on that day are enormous.