The pond is long and narrow, corresponding to the rather narrow Isenach valley. It is about 500m long and 50-80m wide.
The Herzogweiher was already artificially dammed in the Middle Ages and first mentioned in 1408 as Fischwoog. In 1571 there is mention of an associated mill. In 1583, Count Palatine Johann Casimir had an additional water reservoir built to supply the pumps of the salt works. In 1742, the dam was raised because the pumps of the graduation works in Bad Dürkheim were operated with water power from the Isenach until 1850.