From the beginning of the 19th century, Lake Esrum played a role in the transport of firewood from Grib Forest to Copenhagen. From 1802 to 1805, a canal was constructed between the north end of the lake and Dronningmølle. Here firewood was loaded onto large cargo ships and sailed to Copenhagen. The canal was 9 km long, 9 m wide and 1.5 m deep. The work was led by Adolph von der Recke and carried out by local peasants, soldiers and forced labour workers. A towpath ran on the banks of the canal and on the western shores of lake Esrum. The timber had to pass a 4-metre crater-like ramp called "Væltningen", which connected the upper section of the canal to its lower part. The upper part of the canal passed two ponds. One of them, Storedam (Great Pond), was the site of a watermill which was first used as backup for the gunpowder mill in Frederiksværk during the English Wars and later for the manufacturing of textiles for the army. Transportation of firewood on the canal continued until 1874 and it was later used for leisure trips. It has now dried out and been covered by forest, but Væltningen and other elements are still visible in the landscape.