Massacre of Schletz
5000 BCE.
Shown on the map at 48.585°, 16.472°.
In the Massacre of Schletz, more than 200 Neolithic people were killed by blunt force around 5000 BC, towards the end of the Linear Pottery culture epoch, before being dumped in a mass grave on the site of the present-day village of Schletz (in the municipality of Asparn an der Zaya in Lower Austria).
Text from the Wikipedia article Massacre of Schletz, licensed CC BY-SA 4.0.