The river Binnendieze has always been an important river to the city. 's-Hertogenbosch was founded as a small walled city, the size of the present Market square and some surrounding alleys. Later, the city was walled again, this time as big as the current city centre. The rivers within the city walls where named the Binnendieze. The Binnendieze was used for water supply, as a washing and fishing area, but also as a dump. Up until 40 years ago, the river used to be an open sewer. By constructing a sewage system, the Binnendieze slowly disappeared. This was prevented in 1972 by proclaiming the Binnendieze as protected city area. The water underneath the city is now one of the most important historical attractions of 's-Hertogenbosch. You can cruise down the Binnendieze from April - October.