Despite the calamity and huge death toll, Lisbon suffered no epidemics and within less than one year was already being rebuilt. The new city centre of Lisbon was designed to resist subsequent earthquakes. Architectural models were built for tests, and the effects of an earthquake were simulated by marching troops around the models. The buildings and big squares of the Pombaline City Centre still remain as one of Lisbon's tourist attractions. Sebastião de Melo also made an important contribution to the study of seismology by designing an inquiry that was sent to every parish in the country.