The start of this geologically highly interesting round trip is in Bad Ragaz. After the village centre, you turn onto the old, picturesque road towards Valens, where you have to climb 300 metres in altitude for the first 4.5 kilometres. A panoramic stop on the Tamina Bridge, which opened in 2017, is a must. With a span of 260 metres, it is the largest arch bridge in Switzerland. From Pfäfers, follow the gently ascending main road into the Tamina Valley. The next stop is worth a stop at the Windegg viewpoint in front of Vadura. Here you can enjoy a wonderful view of the Glarus main thrust and the Wildseehörner. World Heritage information boards, viewing judges and cool loungers invite you to linger... but you probably want to go further.

At kilometre 16 you reach Vättis, where the exhibition 'BergeQuake!' shows the connection between earthquakes and mountain building in the Sardona tectonic arena... very impressive thanks to the live transmission of seismic recordings! Over the next few kilometres at the bottom of the bubbling Görbsbach, you can enjoy the view of the rugged limestone formations of the Haldensteiner (2,805 m) and Felsberger Calanda (2,697 m). The Eggwald mountain restaurant in Ober Kunkels (1148 m a.s.l.) invites you to stop for a bite to eat. A last short ascent, you have reached Graubünden soil and soon also the Kunkelspasshöhe (1,357 m a.s.l.). The garden terrace of the mountain inn Überuf is irresistible. The lovely pass plateau presents itself like an arena, surrounded by the Calanda (2805 m above sea level), the Crap Mats (2947 m above sea level) and the Ringelspitz (3247 m above sea level), the highest mountain in St.Gallen, located in the Tectonic Arena. Inside the inn, an educational information room is  dedicated to the UNESCO World Heritage Site of the Sardona Tectonic Arena.

The descent to Tamins (660 m a.s.l.) leads over a steep and bumpy natural road built during the First World War. The view from the tunnel blasted into the rock is spectacular. You can overlook the Domleschg and even see the Bernina massif in the distance. From Tamins, follow the national Veloland route no. 2 to Felsberg, where you continue along the right bank of the Rhine to Chur. Once again, you can educate yourself in geology: In the Chur Natural History Museum, a comprehensive geology exhibition focuses on the topic of Alpine formation. Then you can easily roll down the Rhine to Landquart and Bad Ragaz... or you can swing to the train station, look up again to the Calanda... and end the round on the railway.