The two Zapatilla Cays sit twelve nautical miles southeast of Bocas Town, their combined landmass barely fifty acres yet anchoring the largest protected marine corridor in Panama's Caribbean province. Declared part of Bastimentos Island National Marine Park in 1988, the twin islands serve as a nesting refuge for hawksbill and green sea turtles, their beaches closed from April through September when egg-laying peaks. The surrounding reef systems harbour more than two hundred coral species and sixty documented fish families, a biodiversity density that rivals Belize's barrier reef yet receives a fraction of the visitor pressure. Zapatilla Grande, the larger eastern cay, hosts the park ranger station and the only visitor infrastructure: a composting latrine, a covered pavilion, and a mooring grid that limits simultaneous boat arrivals to sixteen. Zapatilla Pequeña remains entirely undeveloped, its interior mangrove stand sheltering juvenile reef sharks and spotted eagle rays. Both islands rest on submerged limestone platforms that drop vertically into the Bocas Trench, creating wall dives within swimming distance of shore. The conservation fee introduced in 2019 funds patrol boats that enforce the no-anchor zone and the seasonal fishing closures that have allowed grouper and snapper populations to rebound. The archipelago's isolation kept large-scale resort development at bay, though zapatilla island tour departures now run six days a week from Bocas Marina and Bastimentos dock. Most operators pair the cays with Coral Cay or Crawl Cay, building a five-hour circuit that includes two snorkel sites and a beach stop. The marine park's elevation to UNESCO consideration in 2023 brought stricter group-size limits and mandatory bilingual guide certification, measures that have slowed permit issuance but improved on-water interpretation. Visibility peaks from February through April when trade winds settle and plankton blooms thin, though calmer seas also mean higher demand for the limited mooring slots. Historically the Ngäbe people harvested sea turtle eggs here until the 1970s, a practice documented in the anthropological surveys that preceded park designation. The Spanish name derives from the islands' slipper-like outline when viewed from the summit of Bastimentos ridge, a vantage few visitors reach. Today the ranger station logs more than eighteen thousand annual arrivals, a figure that includes tour groups, liveaboard dive vessels, and the occasional private yacht. Park revenue has funded turtle monitoring stations on three additional beaches and a mobile clinic that serves the outer cays, demonstrating how entrance fees translate directly into expanded stewardship across the marine corridor.