Limón Bay, natural harbour of the Caribbean Sea, in Panama at the north end of the Panama Canal. Approximately 4.5 miles (7 km) long and 2.5 miles wide, it is protected from storms by breakwaters at its entrance. The bay serves as a waiting area for ships about to enter the canal. On its eastern shore are the twin cities of Cristóbal and Colón, the Atlantic terminus of the canal.