JFYR, Coba is a bit primative and somewhat more unreconstructed than the more touristy Mayan ruins. Avoid the lake (about a dozen Caribbean crocs hang out there) and the poison trees (think poison oak), and take a good set of boots.
As to Muyil - looks cool but have never been.
Originally Posted by cozumelcruising
...just a small hand of ruins still can be climbed such as Coba and Muyil..
Amadeus:09 Diamond;Celebrity:10 Summit; HAL: 87 Rotterdam V,89 Nieuw Amsterdam II,93 Nordam III,94 Ryndam III,96 Westerdam III,99 Veendam IV,01 Maasdam V,02 Amsterdam III,03 Volendam III,03 Zuiderdam II,04 Westerdam IV,04 Oosterdam I,05 Zaandam III,06 Statendam V,06 Prinsendam II,07 Nordam IV,08 Eurodam I,08 Rotterdam VI,09 Veendam IV,09 Volendam,10 Nieuw Amsterdam IV,12 Ryndam III;11 P&O:Artemis;RC:07 Splendour of the Seas,11 Navigator of the Seas,12 Majesty of the Seas