August 16, 2007 -- Lightning struck the Castle in 1764. In the centuries that followed, the Castle was misused as a quarry -- castle stones helped to build new houses in Heidelberg. This was stopped in 1800 by Count Charles de Graimberg who made any effort he could to preserve the Heidelberg Castle. In spite of its Gothic interior, it was not before 1934, that the King's Hall was added.