The main place of worship for catholics, this cathedral is also plainly called "The Dome" by locals. It was built in the 1700s while Timisoara was under Austro-Hungarian rule, by Viennese architects. Its plush interior has 9 altars and an Austrian made organ that makes a fabulous sound when played at concerts.
It's one of the main attractions in Union Square and a peak inside is a must! The Dome holds services in German, Hungarian and Romanian. Due to the great acoustics here, if you get a chance, you can try out a concert or two.
If visiting during summer, head in for a visit - it's nice and cool inside! If here in the winter time, try to catch a carol concert, it sounds great!