The Marienburg castle rises sublimely above the roofs of Obergrombach. The imposing yet picturesque limestone walls covered with tangled climbing plants bear witness to the changing fortunes of history and this old, independent town: the failed peasants' rebellion led by Joß Fritz in 1502, the 30 Years War and War of the Grand Alliance. The castle was built from around 1200 and Cardinal Damian Hugo von Schönborn, Prince Bishop of Speyer had the so-called "Lower Castle" extended for use as a summer residence in 1723.

Surrounded by a lower castle with baileys, towers, gates and the owner's residence, the upper castle with its ring wall is the centre of the complex. Today, the castle is privately owned and can only be viewed during the traditional Burgfest, which is held in even years.