Heidelberg Castle is situated on the top of the King's throne. There are many places of interest and historic sites. It has been expanded several times in history to form a mixture of Gothic, Baroque and Renaissance styles. It is the representative work of the German Renaissance. Heidelberg Castle took 400 years to complete and was once one of the largest castles in Europe. The inner structure of the castle is complex, including defensive fortifications, living rooms, palaces and castle gardens. It was a military fortress at that time, and it was also the palace of the elected emperor. Heidelberg Castle was occupied and destroyed three times in the 17th century. During the three decades of war, Heidelberg Castle was badly damaged. Although it was repaired, its scale was far worse than before. We did not boarded the castle. We just saw the appearance of the castle from the campus of Heidelberg University. It's a good historic site.