Castillo San Felipe del Morro

A massive Spanish colonial citadel guarding the entrance to San Juan Bay.

It stands on a rocky headland at the mouth of San Juan Bay, guarding the harbour. UNESCO named it a World Heritage Site in 1983, together with the San Juan National Historic Site, and more than two million people visit each year.

Guarding the Key to the Indies

Puerto Rico was called La Llave de las Indias, "the Key to the Indies," because of its important position. El Morro, with other forts such as La Fortaleza, San Cristóbal and El Cañuelo, protected it from rival powers during the Age of Discovery and Sail. Across the bay, the smaller El Cañuelo helped defend the entrance. The fort's job was to control the entry to the harbour and defend the Spanish colonial port city from enemies coming by sea.

From a tower to a giant fort

Construction began in 1539 under the conquistador Diego Ramos de Orozco, starting with a small fortified tower named after King Philip II. By 1595 it had grown into a bastion fort, and over the next 200 years it kept growing until it reached its present form in 1787. It has six levels, and its walls are 5.5 to 7.6 metres thick.

On the globe

The model shows the massive stone fort on its headland at the entrance to San Juan Bay.