The European Council adopted France's Heritage Days in 1991. Started in 1983 her the Journées de la Patrimoine have become a tradition with more than 12 million people visiting historic buildings each year. The 31st this weekend will see 17,000 different sites open their doors to the public. One of the sites open to the public is the Montsouris réservoir in Paris, a water storage facility that has been closed for the last 20 years.
