The entire Yucata'n peninsula is peppered with astonishing relics and ruins of the Mayan past as well as comfortable places to stay when you are seeing them. Guides at the sites are usually knowledgable, multi-lingual and often highly educated. They are mostly Mayans themselves and speak to one another in a very much alive Mayan tongue. We found the relatively uncommercial Caribbean coast most to our liking, but no first-time visitor to the peninsula should miss these major sites:
UXMAL: Majestic and awesome, this Mayan city was inexplicably abandoned and reclaimed by the Mayans several times over. There is a sound-and-light show for those who stay overnight or those on the afternoon trip from Me'rida which features an afternoon tour of the ruins, dinner at the elegant Hacienda Uxmal and the show. The narration is on the thin side, but is more than compensated for by the lighting.
CHICHE'N ITZA': Perhaps the most famous ruins of all, especially since the discovery of the serpent shadows that appear to undulate down the side of the the great pyramid the Conquistadores irrelevantly named El Castillo. The serpent appears only on the days of the spring and fall equinoxes. The mathematical computations that went into that construction are as dazzling as they are mysterious. We know the Mayans had the concept of zero, but surely no Apple-et-al. Awesome. The serpent phenomenon was only rediscovered in the past few years--a not too surprising lapse of information, our guide told us, because the weather is usually rainy, or at least cloudy, at either equinox. It is also not a good time to go, in any case, because whatever that serpent meant to the Mayans, today it attracts, said our guide with undisguised horror, "every cult, sect or self-proclaimed mystic within reach." The vast acreage that separates the structures at Chiche'n becomes packed with "foreigners." (To our guide, Andreas, that meant, simply, anyone who was not Mayan.)
Spend two or three nights at the Mayaland or at the Club Mediterane'e-operated Villa Arqueolo'gica, so you can time your visits to the two sites to avoid the tour buses from Cancun and Me'rida. Do not miss the mammoth and still water-filled cenote, the natural sunken reservoir--nearly 200 feet in diameter and almost as deep--still filled with remains of human sacrifices and irretrievable treasure. Be warned, however, that it's also full of mosquitos.