AQUÆ Helvetiæ, described by Tacitus as a municipal town, and much frequented for its excellent water; and though he does not mention its name, Cluverius supposes it to be Baden, in Switzerland, on the rivulet Limat, which soon after falls into the Aar. It is called the Upper Baden, to distinguish it from another called the Lower Baden, in Alsace. E. Long. 8. 49. N. Lat. 47. 55.