Postcard of Matthias Church in the Hungarian capital of Budapest, part of the longly-named "Budapest, including the Banks of the Danube, the Buda Castle Quarter and Andrássy Avenue" World Heritage site. The origins of the church go back to the eleventh century. During the Ottoman period, it became the city's main mosque. After regaining its status as a church, it became the coronation site of many Hungarian kings.
Thanks to my Dad for sending this card, along with this one and this one, from his trip "behind the Iron Curtain" and setting me off on my postcard adventures many years ago.
Stamps are from a 1986 set of six on Hungarian castles. Shown is Baroque Forgách Castle, in Szécsény in northern Hungary.