The principal Ottoman mosque of Trebinje, built in 1719 by Osman-paša Resulbegović, the local Ottoman governor who also built the surrounding old-town walls. The mosque sits at the centre of the walled enclosure; its single dome and slim stone minaret are the dominant features of the old-town skyline.
The mosque was extensively restored in the 2000s after damage during the Bosnian War. The interior is plain — typical Ottoman provincial work, no elaborate calligraphy or tile-work — but the surrounding courtyard with its single old plane tree is one of the more atmospheric corners of Trebinje. Open to non-Muslim visitors outside prayer times; remove shoes and dress modestly.