The vast Fortaleza de San Carlos de la Cabaña, known as ‘La Cabaña’, running beside the harbor, was constructed after the English capture of Havana in 1763. The largest of the military structures built by Spain in the Americas, this fortress was completed in 1774 and its presence formed an effective complete deterrent against the country's enemies. The polygon, occupying an area of around 10 hectares, consists of bastions, ravelins, moats, covered walkways, barracks, squares and stores.  It is impressively well preserved, and the gardens and ramparts are romantically lit in the evening. This fortress hosts the spectacular nightly ceremony of El Cañonazo de las Nueve (cannon fire at 9), the firing of a cannon that marked the closing of the city gates, one of Havana's longest-held and most attractive traditions.

The Catedral Ortodoxa de Nuestra Señora de Kazán (Nuestra Señora de Kazán Orthodox Cathedral), declared World Heritage Site by UNESCO, is one of the newest constructions in Havana, being built in 2000. This Russian Orthodox church is Byzantine in style. It has six beautiful domes, two of which (the biggest and smallest) are gold-sheeted, and the rest are made of bronze. Its staircase entrance calls our attention and is considered the second largest staircase of all outside Russia. From the interior, its golden altar stands out, built in Trinidad and the San Sergio Monastery, Russia; and the murals adorning its walls.

The Cannon Blast ceremony (El Cañonazo de las Nueve) is one of the oldest and attractive traditions of Havana. In colonial days, the shots signalled the closing of the gates of the walled city and the rising of the chain across the entrance to the harbour. The tradition of firing a cannon every night at 9:00 pm was kept even after the wall was torn down and is still used for checking your watch.

Perhaps the most iconic of all Cuban fortresses. Its construction began in 1589 and was completed in 1630, playing a key role in the defence of Havana against raids by corsairs and pirates.  When the English attacked and captured Havana in the year 1762, the castle was damaged and later as soon as Spain took power again it was rebuilt and modernized. A lighthouse was added to the Morro in 1764. Standing 45 metres above sea level, it has become an unmistakeable symbol of Havana.