I know this is an english forum and we should post in english but i don't think the site has it in english so i am sorry....

look here: http://Erlebniswelt.Liliput.ch/

or you could go to Nilpfi it's in solothurn right behind the train station so you don't need a car..(they speak a little english, but the website is german sorry)
www.nilpfi.ch