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.

The neighbors of the town insisted to the town council on the need to create a new public square for their amusement. In 1587, the town council decided to use as a public square the area behind the Convento de San Francisco, which was being built at the time. During the latter decades of the 16th century, this square was called the Plaza Nueva (new square), but from the 18th century onwards, once the Plaza del Cristo had been built, it began to become known as the Plaza Vieja (old square). The most remarkable feature of this square are the buildings around it, with their unquestionable historical and artistic importance of having been the blueprint for a style of architecture which, along with certain developments, subsequently spread throughout the city and characterised the Cuban architecture of the 18th century.

The Museo de Bomberos (Firefighters Museum) is located in the same place where more than 20 firemen died during a great fire. The purpose of this museum is to promote fire prevention throughout the population and to recognize the great work firemen do. The museum contains a bronze sculpture of a fireman, several water tanks, firefighter uniforms, and other related items. It also has an auditorium and offers guided tours and fire prevention courses for children and teenagers.

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.