Above Oensingen is Roggenflue. It's a climbing crag with some 2 or 3 pitch routes. From Oensingen we are driving towards the restaurant Roggen, pass the castle Neu Bechburg.
Please check www.klettergebiete.ch when you can climb in Roggenflue. At the moment the area is closed from April 1st to June 30th. Sadly, there is no information in the newly published guidebook Solothurner Jura.