Since the beginning of this square, in times of the Catholic Kings, it has been a market place with pillars or fountains with running water. It has also been used as a platform for theatre performances, an arena for corridas, a scenario for executions, masquerades, luminaries, cañas games and processions. This is where the townspeople received the monarchs and members of their family during their royal visits and they also declared their loyalty to a king when he ascended the throne or where they mourned over a deceased king. Government buildings have been added to this big rectangular square since the beginning of the Modern Ages until now.

The current aspect of the square shows a neo-baroque marble fountain from the end of the 19th century, made at the workshop of Germano José do Salles in Lisbon. A pedestal comes out of a big round pond with cupids blowing on cornucopias sitting on dolphins. This pedestal holds two small ponds, which look like two round trays, profusely decorated with plant motifs. At the top there is a Corinthian capital. The preserved arcades are the result of several reforms.