Heidelberg Castle

Heidelberg Castle, a Renaissance masterpiece built between the 13th and 17th centuries, houses the world's largest wine barrel — the Heidelberg Tun — with a capacity of 220,000 liters. Constructed in 1751 from 130 oak trees, the barrel anchors a complex that draws 1 million visitors each year. While #3 Wartburg Castle is older and better preserved, Heidelberg's dramatic ruins and colossal barrel make it a more visited attraction than the average German castle, offering breathtaking views over the Neckar River valley from its hillside perch at 200 meters above sea level. The castle's partial destruction by lightning in 1764 left iconic red sandstone walls, and its 1689 burning by French troops during the Palatinate campaign adds to its romantic ruin appeal. Visitors can explore the German Pharmacy Museum inside, housing over 20,000 artifacts.