All About San Gervasio
To go to the Mayan Ruins of San Gervasio, you can take a taxi, take a bus tour (offered by cruise ships, Cozumel travel agencies, and small kiosks around town), take a private island tour by van which includes San Gervasio, or drive yourself in a rental vehicle or motor scooter. Take the Transversal Highway (the road that runs east-west across the island) 11 kilometers east of town, and on the left hand side (the north side of the highway) you will see a large reproduction of an ancient Mayan temple marking the entrance to the park road leading to the ruins. Pass through the gate and wave at the attendant as you go by; there is no need to stop here.
The Mayan Ruins of San Gervasio are in a Mexican National Monument that itself lies within a Quintana Roo State Park. When you turn north off of the Transversal Highway unto the 6 kilometer long park road that leads to the ruins, you are in the State Park. The upkeep of this road, the free (and very safe) parking lot at the end of it, the restrooms, snack bar, gift shop area (the Parador Turistica), and the free map you will receive with you ticket is paid for out of the $4.00 USD per-person entrance fee you pay at the entrance to the Parador. This fee can be paid in US cash or Mexican pesos, but no credit cards are accepted. Once you pass through the Parador area, there is another ticket stand that is run by the Mexican national Government through its agency INAH, or the Instituto Nacional de Antropologia e Historia. The $4.00 USD fee this organization charges (which is in addition to the earlier $4.00 State Park fee) covers the upkeep of the ruins themselves, ongoing archaeological studies, night watchmen salaries, and groundskeepers salaries.
In the Parador area between these two ticket counters you can hire a guide from the official Guide Union who can take you on a private tour. The fee for this service is $18.00 USD, and they fully expect a handsome tip. The guide you get may, or may not, have a firm grasp of English. The stories they tell are sometimes quite fanciful, so if you are interested in the real history of the ruins, I would strongly suggest purchasing a copy of The Yellow Guide to the Mayan Ruins of San Gervasio, on sale at the State Park ticket stand (the first one you pay at) as well as the gift shops in the Parador, Cinco Soles in downtown Cozumel, and Amazon Books (as a kindle eBook or paperback) or EverythingCozumel dot com
Bring plenty of mosquito repellent, a hat, sunscreen, and plenty of bottled water. Good shoes are a must, as the pathways are uneven stone and often muddy. During rainy season, a collapsible umbrella is a good idea. There is no charge for photography, but tripods are not allowed without a permit.
The park is open 8AM to 4PM, but you cannot enter the road to the park after 3PM.