The 21-kilometer strip of tropical dry forest, mangroves, and inland estuary south of Las Peñitas  provides habitat for hundreds of species of migratory birds, as well as crocodiles and other wetland creatures, and is also an important nesting beach for sea turtles.
The park is named for a man who, in colonial times, made his living hunting deer on the island and selling the meat in the market of Subtiava.
Many León-based tour operators  run trips to Isla Juan Venado, but you can just as easily strike a deal with one of the many boatmen in Las Peñitas to explore the endless, tree-lined channels.
Arrange your trip at least one day in advance, especially if you plan on a sunrise excursion, when you’ll see the most wildlife (late afternoons are good, too). Take sun protection and lots of water. You’ll need to purchase tickets at the ranger station/youth club ($2 pp includes life vest), a two-story house 100 meters down the beach from Barca de Oro. The youth club helps with reforestation of the mangrove forests, turtle monitoring, and other types of ecological research in cooperation with the organization FUNDAR.
Like many protected areas in Nicaragua, Isla Juan Venado is comanaged by the local community and an NGO, in this case LIDER. This is one of the most successful examples of the COMAP (co-management) program in Nicaragua, and the ranger station can be a good source of information on this topic, as well as other issues concerning the flora and fauna of the reserve. They can also arrange boat trips to the island for $50 per group of up to 14 or $20–30 for a smaller boat with one of the community members.
Also available are nighttime turtle-viewing trips (seasonal) for $10 and mandatory guided camping also for $10. Some of the hazards in the reserve include caimans, bees, snakes, and crab and turtle egg hunters frustrated by poverty, so bringing a local guide is a really good idea.
You can also access the reserve from the rustic community of Salinas Grandes on the south side of the island, where you can rent kayaks and stay in beachfront ranchos at Rigo’s Guest House (tel. 505/2311-3306 or 505/8647-3146, rsampson [at] ibw [dot] com [dot] ni). Make arrangements at least one week in advance to make sure that Rigo is ready.