
The Maya city with the pyramid on every postcard — El Castillo, the Great Ball Court and the Temple of the Warriors, about two hours from Mérida. Admission is a federal INAH fee plus a Yucatán state fee, the pyramid cannot be climbed, and going early beats both the heat and the coaches.
3-4 hours on site, about 2 hours each way from Mérida$$Tickets on Tiqets → 
The finest Puuc-style Maya city in the Yucatán — the Pyramid of the Magician, the Nunnery Quadrangle and the Governor's Palace, carved in intricate stone mosaics about an hour south of Mérida. Quieter than Chichén Itzá, and a UNESCO World Heritage Site.
2-3 hours on site, about 1 hour 15 minutes each way from Mérida$$Tickets on Tiqets → A small-group day from Mérida that strings together Chichén Itzá, a swim in Ik Kil cenote and a stroll through yellow Izamal, with lunch and transport handled. Note that Chichén Itzá admission is paid separately at the gate.
About 11 hours door to door$$Book on Viator → A Mérida day among the cenotes of Homún, where horse-drawn carts or bikes take you to three limestone sinkholes and you swim in turquoise water far below ground. Entry, snorkel gear and lunch are included on this popular tour.
6-7 hours including transport$$Book on Viator → A small-group walk through Mérida's markets and plazas tasting Yucatecan classics — seasonal fruit, local drinks, ceviche, gelato and traditional sweets — with a bilingual guide. Highly rated, about three and a half hours, and the best first-night orientation to the city.
About 3.5 hours$$Book on Viator → A two-hour guided walk across Mérida's historic centre, from the cathedral and Plaza Grande to colonial mansions and the stories behind the city's founding on a Maya site. Highly rated by hundreds of travellers, and ideal for a first morning.
A boat trip through the Ría Celestún Biosphere Reserve, where thousands of pink flamingos feed on the shallows and mangrove tunnels open onto a quiet lagoon, finished with a beach lunch. A day trip from Mérida with well over a hundred happy reviews.
About 7.5 hours including transport$$Book on Viator → 
Mérida's big modern museum of Maya civilisation, in a ceiba-inspired building north of the centre, with more than a thousand pieces from steles to jade and living Maya culture. Allow two hours, and check the closing days before you go.
FreeA Pueblo Mágico painted warm yellow, with a vast Franciscan convent built over a Maya temple and the huge Kinich Kakmó pyramid on the edge of town. Free to wander, about an hour and a quarter from Mérida, and best in the late-afternoon light.
3-4 hours (or a half day)Details → FreeThe free heart of Mérida: the shady Plaza Grande, the 16th-century cathedral, the Casa de Montejo and the Government Palace murals, then a stroll up the mansion-lined Paseo de Montejo. Mérida also runs a free guided tour from City Hall on most mornings.
2-3 hours (or every evening)Details →