Karlsplatz (Karl's Square), which was named after Grand Duke Karl Friedrich of Baden, occupies an area that held a Franciscan monastery until 1803. Unusually spacious for Heidelberg's Old Town, it provides an unhindered view of the Castle, which Joseph von Eichendorff once praised as "Germany's largest and most beautiful ruin". Its enormous attraction cannot be explained entirely by its history as a residence of the Prince Electors.
The imposing ruin of the Castle, which was damaged in 1689 and 1693 during the Palatinian War of Succession and struck by lightning in 1764, was already fascinating visitors 200 years ago.
The French immigrant Count Charles de Graimberg succeeded in preventing the Castle ruin, which until then had been plundered and used as a quarry, from disintegrating completely. Romantics like Achim von Arnim and Clemens von Brentano discovered and eulogized its beauty and historical uniqueness. The first plans to completely rebuild the Castle were already forged before 1900. But initially only the side of the Friedrichsbau (a lovely Late Renaissance palace) facing the town was repaired.