On the right bank of the Golden Horn in Istanbul there is a small cozy church made entirely of iron. This is the Bulgarian orthodox church of St Stefan. While not the only metallic church in the world, it is definitely the biggest and it is made exclusively of cast iron, which cannot be said for any other Christian religious building anywhere, making the St Stefan church a unique architectural gem.
So how and why was it built? In the 1840-s the influential Bulgarian Stefan Bogoridi donated a court with a few wooden buildings and one of the buildings was chosen to be a church for the many Bulgarians living in Istanbul at the time. Then, in 1870 the independence of the Bulgarian church (from the Greek one) was declared at the spot, so it became one of the most important places of the Bulgarian National Revival. Howеver a fire burnt down the wooden structure and the newly independent Bulgarian nation decided to built a much more stable structure that can withstand both fires and the tricky terrain of the Fener neighbourhood. An Armenian architect by the name of Hovsep Aznavur gave the idea of making the church from cast iron and since iron was the most stable of all materials and very suitable for the weak ground - everyone agreed. An Austrian company by the name of Waagner was chosen to cast the parts in 1893-6. They weighed more than 500 tons. and were transported to Istanbul by ship over the Danube and the Black Sea. After an year and a half work the church was inaugurated on 8.9. 1898.
The church is built in a mixture of Neo-Gothic and Neo-Baroque style; it is a three-domed basilica with 40m (120 ft) tall bell tower. What amazed me during my visit is that actually absolutely everything in it is made of iron - even the altar, the inside decorations, everything. The atmosphere is unique and the inside was very cool even in the blazing august sunlight outside. However, despite the constant efforts to be preserved, the church is very rusty and in pretty bad condition - it turned out iron was really not the best building material; nevertheless the church is an unique and interesting monument
Coordinates: 41° 1′ 55″ N, 28° 56′ 59″ E
The website of the Bulgarian church in Istanbul (in Bulgarian)