Parque Nacional Isla Contoy

Isla Contoy is the antidote to the Hotel Zone: a long, thin island with no hotels, restaurants or new building of any kind, set aside for seabirds and nesting turtles. It lies about 30 kilometres north of Isla Mujeres, is around eight and a half kilometres long, and has been protected since 1961. It became a national park in 1998 and was listed as a Ramsar wetland of international importance in 2003. The park is run jointly by the conservation group Amigos de Isla Contoy and Mexico's environment ministry.

The numbers explain why it is worth the effort. More than 150 bird species have been recorded, with frigatebirds and brown pelicans among the most visible, and loggerhead, green, hawksbill and leatherback turtles nest on its beaches, with nesting visible from April to November. Whale sharks also use the surrounding waters.

Access is tightly controlled. Only 200 visitors are allowed each day, and you can only go with an authorised tour, which leaves from Cancún, Isla Mujeres, Puerto Juárez or Punta Sam. The crossing takes one to two hours depending on the boat, the weather and the starting point. Tours usually combine the island with snorkelling on the Ixlaché reef and a stop on Isla Mujeres, and most include meals and drinks on board. Because of the daily limit, book well ahead in high season. North winds can close the port, particularly in January.

On the island, resident biologists lead guided walks, including to the Puerto Viejo lagoon where birds nest, and the marked trails can only be walked with a guide. A 20-metre observation tower gives the best view over the nesting colonies and the lagoon. There is also a small ecology museum, a souvenir shop and shaded rest areas with grills, plus white-sand beaches in designated zones, including the dunes at the northern end. The park charges an entry fee in addition to the tour price, payable in cash.

The rules are strict and worth taking seriously. Sunscreen and insect repellent must be biodegradable, food may only be eaten in designated areas, and smoking, alcohol and fishing are not allowed. Do not touch or feed wildlife, take anything natural away or leave litter. When snorkelling at Ixlaché, keep at least two and a half metres from the coral.

Contoy suits birdwatchers, photographers, families with older children and anyone who wants a quieter day on the water than the party boats offer. The park is open year-round, from 9:00 to 18:00 when the weather allows, and snorkelling conditions are usually best between May and October, when the sea is warmer and calmer.