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.

Plaza de Armas surrounds a statue of the patriot Céspedes and is ringed by shaded marble benches and second-hand bookstalls. This square, founding in 1519, was the city's first open space, around which the most important political, military, religious and civil institutions were located. The palaces that surrounded it during the 18th century are worthy exponents of Cuban Baroque architecture. On the square’s eastern side a small neoclassical temple, El Templete, marks the spot where the first Catholic mass was celebrated in 1519. Next door is one of the city’s most luxurious hotels, Hotel Santa Isabel. To the north, the squat but angular and moated Castillo de la Real Fuerza (Fort of the Royal Forces) is one of the oldest forts in the Americas.  

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.