Soon after the Erkelenz was elevated to a town status in the 12th century, work began on the brick fortifications of the place. These probably consisted of basic ramparts as had been common since time immemorial for the defence of settlements. Although the castle was not documented until 1349, the town appeared to have developed under the protection of the castle.
The castle has 23 high keep, curtain walls and corner towers. It was part of larger city walls. It was badly damaged by French army in 1674.
The Jan Hus Memorial stands at one end of Old Town Square. The huge monument depicts victorious Hussite warriors and Protestants who were forced into exile 200 years after Hus, and a young mother who symbolises national rebirth. The monument was so large that the sculptor designed and built his own villa and studio where the work could be carried out. It was unveiled in 1915 to commemorate the 500th anniversary of Jan Hus' martyrdom. The memorial was designed by Ladislav Šaloun and paid for solely by public donations.
Born in 1369, Hus became an influential religious thinker, philosopher, and reformer in Prague. He was a key predecessor to the Protestant movement of the sixteenth century. In his works he criticized religious moral decay of the Catholic Church. Accordingly, the Czech patriot Hus believed that mass should be given in the vernacular, or local language, rather than in Latin. He was inspired by the teachings of John Wycliffe.