The Museo Alejandro de Humboldt (Alejandro de Humboldt Museum) is located in a Colonial house in Plaza de San Francisco de Asís Square, in Old Havana, Cuba. Its name comes from the German scientist Alejandro von Humboldt, who is seen as the second person to discover Cuba. This is a scientific museum dedicated to biology and its main objective is to preserve research and promote the historical Humboldt’s legacy. This institution enhances the labor of Cuban and international personalities whose contributions are considered relevant for the development of culture in general terms. It exhibits the historical trajectory of the scientific and botanic data he compiled throughout the island at the beginning of the 19th century, as well as a botanic exhibition which is fundamentally made up of ferns. In this museum there is a perfect copy of a Kritosaurus skeleton found in the desert and donated by the Mexican government, as well as an enormous Pterosaur skeleton, which is around 10 meters length. The House also has a conference room with capacity for 100 persons and a specialized library on German literature.

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 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.

This square dates back to the first half of the 17th century. Its location, just a few metres from the bay, led to it becoming an important trading square over the years. It is said that around the year 1600 the first fountain of the city could be seen at this square. In 1836 it was replaced by a beautiful fountain made of white Carrara marble by Giuseppe Gaggini, under the good auspices of the Villanueva Count. This fountain is called Fuente de los Leones (Lions Fountain). On its paved area stand two noteworthy buildings: the Monastery and Basilica of San Francisco de Asís, which today houses the Museum of Religious Art and a concert hall. It is also where the Lonja del Comercio (Chamber of Commerce) is located, inspired by Spanish Renaissance architecture and topped by a dome on which a sculpture of the god Mercury stands. Among the houses built around the plaza, the house of the Arostegui family, residence of the Captain Generals until the completion of the City Hall at the end of the 18th century, was erected.