Rennfeld, Mountain summit in Styria, Austria.

Rennfeld is the westernmost peak of the Fischbach Alps, rising to 1,629 m between the Mur and Mürz rivers above Bruck an der Mur and Kapfenberg. Its narrow, largely wooded southwest-northeast ridge widens at the top into an open plateau holding the Ottokar-Kernstock-Haus and a large summit cross dedicated to the fallen of both world wars. A directional radio station also stands on the plateau.

The name Rennfeld comes from a legend set in the 11th century: Wulfing von Stubenberg returned from a crusade on the wedding day of his betrothed Agnes von Pernegg and killed her groom Rüdiger von Kuenring in a duel on the open summit, dated 17 May 1009. A cairn there is said to be Rüdiger's grave. Since 2014 the northern flank has belonged to Sankt Marein im Mürztal, and the summit marks the meeting point of three municipal boundaries.

The mountain's name comes from a legend set in the 11th century: Wulfing von Stubenberg returned from a crusade on the wedding day of his betrothed Agnes von Pernegg and killed her new husband Rüdiger von Kuenring in a duel on the open summit, said to date from 17 May 1009. A cairn there is said to be Rüdiger's grave, and Agnes's braid is displayed in the Loreto Chapel at Oberkapfenberg Castle.

Several marked trails start from Frauenberg and lead to the summit with options for different experience levels. The Ottokar-Kernstock-Haus sits lower on the mountain and provides a place to rest during your hike.

The summit plateau holds a directional radio station linking the Aflenz earth station to the network and relaying signals from transmitters 45 and 46 km away. The large summit cross is inscribed as a memorial to the dead of both world wars.