The Ponts Couverts - The Covered Bridges of Strasbourg is a set of three bridges and four towers that were set up to defend Strasbourg. Each of the bridges were once covered by a wooden roof although the roofs were removed in 1784 but the name Ponts Couverts covered bridges has stuck nevertheless.  After the annexation of Strasbourg to France in 1681 another set of fortifications was built by Vauban to acccompany the Vauban Dam.