Rheinfelden is 1st described about 851 as Rifelt As well as in the 1st 50 % of your twelfth century it absolutely was termed Rinfelden.[eight] In the 2nd 50 % with the tenth century, all the Fricktal place—the Frick valley, a finger of land in northwestern Switzerland east of existing-working day Basel, amongst the Jura Mountains on the south, al