Open stable place for gelding

Open stable place for gelding - I am looking for my 13 year old gelding from summer/early fall an open stable place in Karlsruhe and surrounding area. He is 1.65cm tall and has front irons.
I myself am a recreational rider and 29 years old.

I would like an open stable, at night his own box would also be fine, otherwise I would like a lot of freedom of movement for him. Gladly a pure gelding herd.
About a riding arena and a nice riding area we would be happy.

If someone has an idea, please contact me.