State Art Gallery / Orangery

In addition to the art collection, there are also buildings worth seeing at Zirkel. Behind them is the botanical garden.
A virtual tour is offered here: kunsthalle-karlsruhe.de

The Staatliche Kunsthalle Karlsruhe is a museum of fine arts and houses paintings by mainly German, French and Dutch masters from a total of eight centuries.
The building, built by Heinrich Hübsch between 1836 and 1846 as the Grand Ducal Picture Gallery and expanded in several phases, is one of the oldest museum buildings in Germany. It was specially created for the extensive art collection of the Baden princely house, the basis of which is the so-called Mahlerey Cabinet of Margravine Karoline Luise (1723–1783).
See de.wikipedia.org/wiki/Staatliche_Kunsthalle_Karlsruhe

The Staatliche Kunsthalle Karlsruhe is a museum of fine arts with paintings by German, French and Dutch artists from 8 centuries.
See: kunsthalle-karlsruhe.de