The monument consists of the Castle, the ruins of the Alcazaba Palace, the Plaza de Armas, an extensive viewpoint over the city, a museum nucleus, an archaeological nucleus, areas of gardens and walls.

The monument occupies an area of about 4 hectares and is delimited by a huge belt of walls and ramparts that correspond, in part, to the limits of the old alcazaba of Lisbon.

Jerónimos Monasteries, a masterpiece of Portuguese architecture, the Royal Monastery of Santa Maria de Belém, commonly known as the Jerónimos Monastery, because it was intended for the Order of Saint Jerome, has been classified as a National Monument since 1907 and was inscribed on the UNESCO World Heritage List in 1983. The church, with religious service and hours for heritage visits, and the cloister, secularized in the nineteenth century, form the most visited heritage complex in the country.

Monument to the Discoveries, the architectural design is by Cottinelli Telmo and the sculptures are by Leopoldo de Almeida. In a prominent position on the right bank of the Tagus River, the original monument, made of perishable materials, was erected in 1940 on the occasion of the Portuguese World Exhibition to honor the historical figures involved in the Portuguese Discoveries. The current replica, in concrete and stone, is later, having been inaugurated in 1960.

This monument was erected with the purpose of serving both as a gateway to the city of Lisbon, and as a defense system against possible invasions and attacks from the Tagus.

This bastion was a strategic point also protecting the Jerónimos Monastery, which were strategic points to invade the city.

King John II of Portugal (1455-1495) is at the origin of this building, as well as the fortresses of Cascais and São Sebastião da Caparica.

The shores of Belém were once protected by a ship, the Grande Nau. This was replaced by the Tower of Belém a few years later, during the last five years of the reign of King Manuel I of Portugal.