Fodor's Expert Review Yamil Lu'um
Located on Cancún's highest point (the name means "hilly land"), this archaeological site is on the grounds of the Park Royal Cancún and Westin Lagunamar, which means that nonguests can visit only from the beachside. The concierges at either hotel may let you enter through their property if you ask nicely, but otherwise head to Playa Marlín and admire the ruins from a distance. Although it consists of two structures—one probably a temple, the other probably a lighthouse—this is the smallest of Cancún's few archaeological sites. Discovered in 1842 by John Lloyd Stephens, the ruins date from the late 13th or early 14th century. Keep an eye out for roaming iguanas.