Thanks for posting the postcard. It's very interresting to see them on a postcard from Vienna.
The words on the postcard "Gruß aus Wien" mean "greetings from Vienna".The right pictures shows Stephansdom, the biggest church in Vienna. On the picture in the middle you find the Rotunde, a buildung that was errected for Vienna World Fair of 1873. Afterwords it was used for fairs, shows and as concert-hall. Sadly it burned down in 1937.