The Telemark Canal extends 105 km from Dalen south-west to Skien, passing through a series of long lakes. It was regarded in the 19th century as a notable contribution to the improvement of transport between the western and eastern parts of Norway. It was built in two stages, the more southerly linking the lower end of Lake Norsjø with Skien being completed in 1861, and the section south from Dalen in 1892. Construction of the latter was made possible by the use of high explosives. There are 18 locks in all, including a notable 5-chamber staircase with a total rise of 23 m at Vrangfoss. The canal carried general merchandise and even some passengers but its main purpose was the floating of timber. The paper mills that used the timber have closed and it is now entirely a recreational waterway, popular with many boat owners. It is also possible to cruise on the canal from Skien to Dalen, or to take day trips that can last as long as 11 hours on two vessels, the “Henrik Ibsen” and the “Victoria”, the latter dating from 1882.