Public domain
Greetings from Cologne. The Hahnentorburg from the 13th century
From the collection of Rijksmuseum, Amsterdam. Free to download, adapt and use — no permission needed.
Credit lineGruss aus Köln. Die Hahnenthorburg aus dem XIII. Jahrhundert. 1885 - 1905. Rudolf Dohmen. Rijksmuseum, Amsterdam. Public domain.