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 is a 1760 Baroque palace venerated for the great beauty of its Andalusian patio. It has a fountain surrounded by tropical vegetation where you will find several tortoises. Before the Revolution, this monumental building was the headquarters of the Industrial Bank; nowadays it houses the El Patio Restaurant. Although it offers traditional Cuban food, it speciality is meat and crustaceous, dishes as the Cathedral Mixed Grill (a varied grill) and skewers of lobsters and shrimps. The bar serves a collection of wines beers, rums and cocktails. It is currently possible to buy souvenirs in the craftworks shop located in the former Casa de Baños House, on the western side of the Cathedral square.

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 Convento de Santa Clara (Santa Clara Convent) is located at the south of Plaza Vieja Square of Havana. This is the biggest and oldest convent in all of Cuba, built between 1638 and 1643, and it is a good example of early Spanish influenced architecture. It was actually the first female convent in the city. The temple stopped serving for religious purposes in 1920, housing for some time the Ministry of Public Works. It is currently part of the restoration team of Old Havana. It being recommended to visit the Colonial-style interior patio, where the first public fountain of the city was found; the cloister, the cells of the nuns and the small cemetery.