The famous Niedermörmter Roman helmet of the 3rd century AD. Side view. This style of helmet with hinged cheek pieces and a large neck protection was found in the river Rhine (now in the Mainz museum). It is a Weisenau type. Along with the elaborate applique and perforated brow, this helmet sports a unique design element on the crown: what are described as either "Mice and cheese" or "Mice and bread". Some experts call this model the most beautiful Roman helmet.