This century was perhaps one of the most difficult periods for the 300 inhabitants of Viareggio ; the area was really bad , for the life , often people died for malaria , but however slowly Viareggio changed its appearance ; two small churches and as many factories were built , followed by a number of small shops . Slowly Viareggio changed its appearance ; two small churches and as many factories were built , followed by a number of small shops .