The Palacio del Segundo Cabo (Segundo Cabo Palace) is located on the north side of Plaza de Armas Square, Old Havana. This majestic palace is Neoclassical in style and was built in 1772 with local limestone full of holes and calcareous marine incrustations. This building was first built as headquarters of the Spanish vice-governor. Currently, and after several reworkings during which it functioned as Post office, Senate Palace, Supreme Court, National Academy of Arts and Letters, or the Cuba Academy of Science, nowaday it belongs to the Cuban Ministry of Culture, and it hosts the Centre for the Interpretation of Cuba-Europa Relationship.

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 Real Force Castle is located in Old Havana, in an attractive area of important architectural, urban, cultural and social values. This is the oldest fortress of the former fortification system of Havana and the Americas, which construction dates back to 1577. It was declared a World Heritage Site by UNESCO. A replica of the La Giraldilla, the symbol of the city, can be seen on the highest tower of the castle (the original is in the Museum of the City). Since 2008, the Museo de Navegación (Maritime Museum) is located in the former moat of the Real Force Castle. This museum houses interesting exhibits detailing the history of the fortress and Old Havana, as well as its connections with the former Spanish Empire. It’s worth mentioning that huge scale model of the Santísima Trinidad galleon can be found here.

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.