Amsterdam, NL
The circular fort at Ossenmarkt (1861), cross the river Vecht by the wooden bridge. See the online [http://www.stelling-amsterdam.org/forten/weesp-fort/info.htm#FOTO images and panorama]. Behind the fort are two older bastions (circa 1674), Bakkerschans and Nieuw Achtkant (with a view of the windmil
Listen to the audio guide for Torenfort aan de Ossenmarkt Free on WIP — starts by itself when you arrive, even with the screen off