This kale (castle) or hisar (fortress) overlooks Afyon from a craggy rock. The strenuous approach up a steep but well-maintained set of stairs passes Ottoman guard towers on what was once a formidable defensive structure. Hittite King Mursilis II built the first castle here, c 1350 BC. Since then, various rulers have restored the original kara hisar (black fortress) – most recently the Turkish government, with unorthodox white masonry. The path is signposted opposite the Ulu Cami.
Although the castle is empty, the views on the way up over the old town are excellent and from the walls sitting on the 226m-high summit you can see the full sprawl of Afyon below. However, by night the path is unlit so do not leave it too late walking down. In 2004 Afyon, named after the afyon (opium) that was cultivated here, was renamed Afyonkarahisar ('Black Castle of Opium'), shifting the limelight to the castle and away from its less savoury history.