Planned as early as the 16th century as a “crane”, a baroque harbour crane with a double jib was built on the Kranenkai at the city wall gate in 1773 to stimulate Main trade, and is now called the Alter Kranen. The impressive industrial, architectural and economic monument has a water level staff and high-water marks and is still used today for the official measurement of the Main level. Due to its unique mechanics from the Baroque period, it is considered one of the most important and also architecturally most beautiful remaining stone treadle cranes, which has a double jib with two chain drives. It is also a popular photo motif and a symbol of the great importance of Main trade in the city of Würzburg.