Naguabo
Cayo Santiago's 1,800 rhesus macaques descend from 409 India imports (1938)—85+ years of primate research offshore while fishermen sell trunkfish pastelillos onshore.
Naguabo exists because a Taíno cacique named Naguabo once ruled here—and because in 1938, a scientist worried about monkeys. The settlement's first incarnation, Santiago, was built in 1513 to ward off Carib raids but abandoned a year later after being burned down. The modern town rose in 1794 on different ground, relocated again in 1821 to its current position, carrying its indigenous name through multiple geographic deaths and rebirths.
What makes Naguabo singular is Cayo Santiago, a 38-acre offshore island that has hosted a free-ranging population of rhesus macaques since December 1938. C. Ray Carpenter, fearing World War II would cut off primate imports from South Asia, established a breeding colony with 409 monkeys from India. Today's population—roughly 1,800 descendants of those founders—has been studied continuously for over 85 years, making it one of the longest-running primate research sites on Earth. Tourists can't land, but boats circle the island watching monkeys that watch humans back.
The human economy revolves around fishing. Generations of families have worked the waters off Punta Santiago, hauling lobster, conch, and local species. The catch arrives fresh at shoreline kiosks hours later. Naguabo claims culinary fame for the pastelillo de chapín—trunkfish wrapped in deep-fried flour dough, a preparation that became an island-wide delicacy.
El Yunque's eastern slopes touch Naguabo's borders, driving eco-tourism alongside the monkey-boat trade. By 2026, the municipality tests whether fishing traditions and research tourism sustain a town that was burned down, relocated twice, and became host to one of science's strangest geographic experiments.