Today, July 15th, is the anniversary of the 1927 incident at the Palace of Justice in which the right-wing paramilitary forces, including the Nationalists, armed the police and attacked protesting social democrats, killing more than 80 and injuring over 600.
A memorial plaque to the victims was dedicated at the Central Cemetery Zentralfriedhof in 2007.
The incident was a rehearsal for further right-wing violence underwritten by wealthy industrialists and the Catholic Church, eventually leading to the fascist takeover in 1934. That's how these things get started. As Hegel said, what we learn from history is that we don't learn from history.
The Central Cemetery is the second-largest cemetery in Europe, apparently, and worth a tour. The gravestones in the Jewish section were most recently desecrated and vandalized in 2012. There are guided tours of the church on site every first Sunday at 9.45h
https://en.wikipedia.org/wiki/Vienna_Central_Cemetery