The mediaeval wall encircling Wetzlar was built section by section between 1250 and 1300. It was 1.7 kilometres long and reached a height of up to 11 meters. Built with shallow, earth-filled arches, the wall had parapets with battlements and loopholes. There were five main gates, none of which have survived, numerous smaller ones, and at least 9 towers. The low-lying land along the small stream called the Wetzbach was protected by a further wall of 350 meters. As the town expanded in the 19th century, much of the wall was torn down. Parallel to the original run of the wall is a string of parks bearing the names of Wetzlar’s twinned towns: Avignon (France), Colchester (UK), Siena (Italy) and Schladming (Austria).