Mérida's position at the centre of the Yucatán makes it one of the best bases for Maya site exploration in the world. Chichén Itzá, the most visited archaeological site in Mexico, is 120km east, roughly two hours by bus or car. The ADO bus leaves CAME station in the morning, gives you several hours at the site, and returns in the afternoon — it is a manageable day trip, though the site itself is large and exposed, and the midday heat in summer can be punishing. Arrive as early as possible.
Uxmal, 80km south on the Puuc Route, is in many respects more rewarding than Chichén Itzá: it receives far fewer visitors, the architecture is more refined, and the jungle setting has been less manicured. The Pyramid of the Magician and the Nunnery Quadrangle are outstanding examples of Puuc architectural style — distinctive for its mosaic stone façades and serpent decoration. Organised tours from Mérida typically combine Uxmal with two or three smaller Puuc sites (Kabah, Sayil, Labná, Xlapak) in a single day, which is worthwhile given that the smaller sites are rarely visited and architecturally significant.
Campeche, the walled colonial city 190km southwest, is possible as a long day trip but better as an overnight. The historic centre, a UNESCO World Heritage Site, has some of the best-preserved colonial fortifications in the Americas, built to defend against pirate attacks in the 17th and 18th centuries. The seafood here is also better than in Mérida; pan de cazón (layered tortilla with shark and black beans) is the local speciality.
Dzibilchaltún, only 16km north of Mérida on the road to Progreso, is often overlooked. The Maya site has a well-preserved temple (the Temple of the Seven Dolls) aligned to mark the solstice sunrise, and the cenote (Sacred Cenote Xlacah) at the centre of the site is one of the most swimmable in the Yucatán — clear, deep, and open for visitors. It is an easy half-day from the city, either by taxi or colectivo from the northern terminals.
Izamal, 70km east, is the "Yellow City" — a colonial town where every building is painted the same ochre-yellow and a large Franciscan monastery sits directly on top of one of the most significant Maya pyramids in the Yucatán. The monastery atrium is the second largest in the Americas. The town is small enough to cover in half a day and is served by colectivo from Mérida.