The attractive geographical location of Cuba, which was called the "Pearl of the Antilles" during colonial times for evident reasons, stimulated the appetite of corsairs and pirates who tried to take control of the village of San Cristóbal de la Habana on several occasions.

In addition to that, the Spanish Court decided to turn the port of Havana into a concentration area for ships laden with the treasures of the New World before departing for Europe.

All this led Spanish authorities to enact a royal edict to build a fortification system to protect the properties of the Crown and keep attackers away if they tried to take the capital of the island.

In December 1563, the King ordered his officials in Havana to build defensive facilities on a high rock at the entrance of the bay, as a sort of beacon for friendly ships and a guardian against the enemies.

The so-called Castillo de los Tres Reyes del Morro, designed along with other major fortresses in Cuba by Juan Bautista Antonelli, an Italian military engineer, was a Renaissance-style building constructed as an irregular polygon, and had three powerful bastions that controlled the bay, the entrance to the harbor and the city.

Governor Don Pedro Valdés, who ruled from 1600 to 1607, was the official who most contributed to the completion of the works of fortification. A solid platform was built during his mandate to place a 12-piece artillery battery called "The 12 Apostles", which still exists today.

At the end of his mandate, only the soldiers' barracks, the arsenal and the water tanks, among other minor facilities, remained unfinished. The works were completed years later with the construction of the La Cabaña Fortress.

Considered the major fortification of the city's defense system against pirates for over a century, the Morro Castle was seized by the English, who eventually took it after opening a breach in one of its walls, and used it to have the capital surrender to them.

Silent witnesses of Havana's development, both fortresses saw the expansion of the city beyond its famous Walls by 1740. However, the habit of announcing the closing of the walls every night by firing a cannon at 9 o'clock has become a tradition that is still followed today.

Night after night, at 9 pm sharp, the guards would fire one the pieces of artillery of the fortress to tell Havana citizens that it was time to take refuge behind the thick walls and avoid walking in the forests of the exuberant vegetation surrounding the city.

The very development of the city led to the destruction of the walls, of which some small remains can be seen today. However, it could not put an end to a tradition that Havana dwellers proudly call "the 9 o'clock cannonshot", which many use to set their watches.

As part of today's ceremony, guards in Spanish uniforms like those worn in the garrison in colonial times march toward the designated piece of artillery to fire it. The guards are closely followed by nationals and foreigners who visit the Morro-Cabaña Historic-Military Park to witness one of the most popular traditions in Havana.

The same cannons used centuries ago keep the tradition alive in an environment where modernity and colonial constructions go hand in hand, under the alert and quiet stare of the guardian of the city.