Cayo Santiago
| Geography | |
|---|---|
| Location | Humacao, Puerto Rico |
| Coordinates | 18°9′23″N 65°44′3″W / 18.15639°N 65.73417°W |
| Area | 0.139179 km2 (0.053737 sq mi) |
| Length | 0.6 km (0.37 mi) |
| Width | 0.4 km (0.25 mi) |
| Highest elevation | 34.9 m (114.5 ft) |
| Highest point | El Morrillo or "Big Cay hill top" |
| Administration | |
| Commonwealth | Puerto Rico |
| Municipality | Humacao |
Cayo Santiago, also known as Santiago Island, Isla de los monos (or Island of the monkeys), is located at 18°09′23″N 65°44′03″W / 18.15639°N 65.73417°W, 0.59 mi (0.95 km) 0.6 mi (1.0 km) to the east of Punta Santiago, Humacao, Puerto Rico. It is known as the home to approximately 1800 rhesus macaque monkeys, who have been observed and studied by scientists since 1938.