The Brömserburg (also called the Niederburg) is a castle located near the banks of the Rhine in the town of Rüdesheim am Rhein in Rheingau-Taunus-Kreis in the German state of Hesse.

However, no antique building fabric has been confirmed and, in particular, it remains unproven that, as previously assumed, it was a watchtower or the bridgehead of a crossing opposite Bingium (Bingen am Rhein) on the left bank of the Rhine.

It was protected by an enceinte and moats; in those days the Rhine flowed, according to historical engravings, immediately past its southern front — unlike today, where there is a road and wide riverbank zone between the castle and the river.

Other buildings were built onto the donjon up to the same height, and completely vaulted in up to four storeys (a unique design for a castle on the Rhine); thus a quadrangular structure was created.

At the same time the courtyard was raised in height and, in the centre, a massive, new bergfried was erected which was joined onto adjacent elements of the second phase without any joints.

In the 13th century, the family of Brömser from the Wisper valley are recorded as castellans (Burgherren) of the castle within the territory of the archbishops of Mainz.

In 1640, the south-eastern corner, facing the Rhine, was blown up by French troops of Duke Henry II of Orleans during the Thirty Years' War, at the same time destroying the upper part of the bergfried and the donjon.