Holy Trinity Greek Orthodox Church in located in the historic Greek neighborhood of Vienna's Innere Stadt. Greek Orthodox churches have existed near this site since 1787, as a result of the 1781 Patent of Toleration issued by Joseph II, Holy Roman Emperor. The architect of the 1787 building was Peter Mollner.
The current building is a Byzantine Revival re-design of the Mollner building by Danish-Austrian neo-classic architect Theophil Hansen. Greek-Austrian diplomat and philanthropist Simon Sinas funded the project, one of many collaborations with Hansen in Vienna and Athens. The cathedral was inaugurated on December 21, 1858.
The exterior features two-tone brickwork and gilded archways. The elaborately ornamented sanctuary shows a stylish allusion to Baroque church architecture typical of southern Germany and Austria. A number of frescoes for the facade and vestibule were commissioned from the Austrian painter and art professor Carl Rahl, with other frescoes by Ludwig Thiersch.
Since 1963 the cathedral has been the seat of the Greek Orthodox Metropolis of Austria.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.