After the 1755 earthquake, the city was rebuilt largely according to the plans of Prime Minister Sebastião José de Carvalho e Melo, the 1st Marquis of Pombal; the lower town began to be known as the ''Baixa Pombalina'' (Pombaline central district). Instead of rebuilding the medieval town, Pombal decided to demolish what remained after the earthquake and rebuild the city centre in accordance with principles of modern urban design. It was reconstructed in an open rectangular plan with two great squares: the ''Praça do Rossio'' and the ''Praça do Comércio''. The first, the central commercial district, is the traditional gathering place of the city and the location of the older cafés, theatres and restaurants; the second became the city's main access to the River Tagus and point of departure and arrival for seagoing vessels, adorned by a triumphal arch (1873) and a monument to King Joseph I.