İğneada Floodplain Forests National Park

This is a foundry and industrial village established in the 15th century to process the local iron and copper ores. There's a mine within the complex, plus accommodation and a mosque for the workers. A canal supplied a waterwheel which pumped bellows for the furnaces. Iron from this foundry was taken to the coast at İğneada and transported to shipyards and to the Imperial cannon factory – it found its way into cannonballs fired during the Ottoman capture of Istanbul in 1453. The foundry was renovated in the 19th century but wrecked in the Russian invasion of 1877/78; after the Great War it was abandoned.

A well-preserved historic village over the hills.

Remarkable complex of caves, 3 km in total, of which you visit 450 m, wear stout shoes. There are three caves of strikingly different appearance. You enter through the lowest, sulu mağara or "wet cave", where a sidewalk follows the creek – in winter this cave floods and is closed. Dripstones are still forming down here. After 250 m only experienced cavers may go deeper, and the bats do as they please, while visitors ascend 60 m on the steps to kuru mağara or "dry cave". This area is richly decorated with stalactites and stalagmites, and you explore 200 m then exit. The third cave kız or "maiden" is also on this level, but closed to tourists: you wouldn't want to disturb 60,000 bats. As to the name "Dupnisa", a fey legend invokes Dionysos, but it's just Bulgarian Дупница (dupnitsa) which means "hole".