Smack-bang in the heart of Trebinje’s old town is the Osman Pasha Mosque. The mosque was built in 1726, making it the second-oldest in town, but there is a monumentality to this that gives it a real ‘best in show’ feel. There is an interesting story behind Osman Pasha himself, the man who built the mosque and had it named in his honour. He was accused of building a bigger and more beautiful mosque than the one dedicated to the Emperor, leaving Sultan Ahmed III no choice but to have Osman (and his nine sons) executed. That might seem a little harsh, but the sentence was carried out in Constantinople in 1729.