Fehtija Mosque is a mosque and former Catholic church located in the town of Bihać, Bosnia and Herzegovina. Built in 1266, it is the oldest gothic building in the country. It was originally built as a Catholic church dedicated to Saint Anthony of Padua, and was subsequently transformed into a mosque following the 1592 conquest of Bihać from Habsburg Croatia by the Ottomans. The building was originally accompanied by a monastery, which was also mentioned in a 13th-century charter of the Croatian nobility.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.