The centerpiece of this biological reserve is a 326-hectare island – the tip of numerous underwater rock formations. Some 15 different species of coral are here, as well as threatened species including the Panulirus lobster and giant conch. The sheer numbers of fish attract dolphins and whales, as well as hammerhead sharks, manta rays and sea turtles.

On the island, at about 110m above sea level, the evergreen trees consist primarily of milk trees (also called ‘cow trees’ after the drinkable white latex they exude), believed to be the remains of an orchard planted by pre-Columbian indigenous inhabitants. Near the top of the ridge, there are two pre-Columbian granite spheres; the rest have been removed. Archaeologists speculate that the island may have been a ceremonial or burial site for the same indigenous tribes.

To preserve the ecology of the island, recreational visitors have been prohibited from venturing beyond the boat-landing beach since the end of 2013. The only way to access the island is via snorkeling and diving tours, arranged by the lodgings in Bahía Drake and by La Perla del Sur in Sierpe. Tour prices are around US$80/135 for snorkeling/two-tank diving tour.