This is the very sneaky way to the Heidelberg castle.
Find yourself on the noble trails of Empress Elizabeth of Austria (Sissi) if you enter the narrow foot path - Valerie walk - behind the Karlstor station via a passage crossing the railway lines.
You reach it quickly just across the river Neckar from the Hirschgasse over the foot bridge by the looks. The valery walk (Valerie Weg) winds itself up tight along the granite rocks and meets up eventually with the Elizabeth path. Both paths names derive from empress Elizabeth and her daughter Valery who both visited Heidelberg between 1883 and 1890 for longer periods.
A secret and not well known path.
You will not meet any tourists, but turn into a local...