Rabenfelsen

A natural sight on the Danube is definitely the Rabenfelsen made of mass limestone in the Danube valley.

Yes, the rock just before Tiergarten is a very impressive sight.

Upper Danube Nature ParkRaven Rocks
White Jurassic, mass limestone
140 million years ago, limestone and silica sponges grew into sponge reefs in the shallow, warm Jurassic Sea, similar to the coral reefs in the South Seas. Limestone was deposited in the cavities of the dead sponges and solidified into hard mass limestone.The reefs were originally covered by other layers:
The ancient Danube washed them out and exposed them 2-10
million years ago. This is how the diverse rock formations in the Danube Valley came into being.Source: Information board at the site