Tragöß (or Tragoess) is a municipality in the district of Bruck-Mürzzuschlag in Styria, Austria. It is home to Grüner See (Green Lake), which dries out almost completely in the autumn. In the spring the lake is filled with snow melt runoff. This gives the lake crystal clear water, the existing rocks and meadow give the lake its green colour.
It is likely that Tragöß was already inhabited by the ancient Celts. The centuries that followed the collapse, in western Europe, of the Roman empire was marked by a period of large scale migrations, and by the sixth century the Tragöß area was inhabited by Slavs, who made their homes not on the valley floors, but on the slopes that overlooked them. Bavarii and Franks followed in the ninth century, settling for the most part the fertile ground of the valley floors.
The first surviving written record of the place dates from 16 May 1023, in connection with the gifting of lands by Emperor Henry II to the Convent of Göß.