Hato Caves — Wikipedia

Hato Caves are show caves, publicly accessible since 1991 and a popular tourist attraction on the Caribbean island of Curaçao. The caves consist of marine coral limestone, which accumulated over millions of years and after sea levels had dropped were exposed to atmospheric corrosion and karstic processes. They are approximately 240 m (790 ft) long and cover an area of 4,900 m2 (53,000 sq ft) .