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.

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 Templete, a small neo-classical style construction, was built in the second half of the 18th Century. It is located in Plaza de Armas. This was the site where the first public mass was celebrated and also the site of the first town council of the nascent town of San Cristóbal de La Habana. The Templete resembles a Doric temple and houses three commemorative canvasses by the famous French painter Juan Bautista Vermey. One of the walls exhibits the plate that declares Old Havana a World Heritage Site.

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.