The 1755 Lisbon Earthquake, with an estimated magnitude of Mw ≈ 8.5, was one of the greatestearthquakes in history. It caused considerable damage in Lisbon, mainly concentrated in theDowntown due to the existence of densely arranged buildings on narrow streets; and on monumentalstructures due to the predominant earthquake frequencies. The ground movement was followed by atsunami and fire, which increased the loss, both in terms of built environment and of human lives.Following the earthquake, Marquês de Pombal was given the responsibility for dealing with theemergency response, and later for the reconstruction of Lisbon. The survey known after his name andthe answers given by the priests, provide even today an important source for studying the aftermath ofthe event.For the reconstruction of the city, Baixa and Chiado districts -which were almost completely destroyed-were razed, and rebuilt according to a new plan incorporating an orthogonal pattern with wider streetsfor increased safety. The buildings were constructed in a system called the Gaiola Pombalina, whichwasn’t a new invention but an intelligent solution that could be “prefabricated”, and thereforecorrespond to a large-scale rebuilding process.