The West Tower of Terreiro do Paço is located on a site that, prior to the 1755 earthquake, contained the Paços da Ribeira (which King Manuel I ordered built in the early 16th century as the official royal residence in Portugal). Part of the structure of the officially named Praça do Comércio – one of the largest squares of its kind in Europe – it has been transformed in recent years into a space for medium duration exhibitions of a wide variety of themes related to the culture and history of Lisbon.