A purpose-built eco-archaeological park 70 km south of Cancun on the Riviera Maya, occupying the site of a Mayan port and trading town. The headline attractions are the three underground rivers that visitors swim through with life jackets, plus replica villages, a butterfly pavilion, a coral reef aquarium, a turtle rehabilitation pond, dolphin and sting-ray encounters (extra cost), and one of the most ambitious nightly shows in Latin America — Xcaret México Espectacular — which traces 500 years of Mexican history with 300 performers.
It is touristy and not cheap (US$130-180 for full-day adult admission), but very well-organised and genuinely engaging — even sceptical adults usually leave impressed. The same group operates the more adventurous Xplor (zip-lines, amphibious vehicles) and the calmer Xel-Há (cenote-and-snorkel) parks nearby; combination passes are available.