Karlsplatz Square is one of the most famous in the city. It's practically right next to the Opera and the Exhibition Hall of Secession. We were standing before a very big square, with the occasional small stand in the middle. It's fountains and several attractions for children and older kids.
It's surrounded by the Secession building, for two other important constructions, the Technical University of Vienna and the Church of Saint Charles, the Karlskirche. This is the one of the most beautiful Baroque churches, with its impressive columns in the entrance and it's enormous green dome. Its dimensions trick you and it looks much bigger than it is.