Canal, opened in 2014, was dug straight through the bed of the Aa. The Aa was led below it, and so all navigation on the Aa east of the Maxima canal ended. In light of the intensity of recreational water traffic on the Aa in 's-Hertogenbosch, this is probably an advantage. Course Near Heeswijk The Heeswijk stretch of the Aa runs for about 5 km from the Kilsdonk Mill to Heeswijk Castle. It is currently under development to create an ecological connection zone, and to restore the river Aa. The Kilsdonk Mill is a rather unique combination of a windmill and a watermill. From Heeswijk Castle to the Maxima Canal The stretch of the Aa downstream from Heeswijk Castle till the Maxima Canal is characterized by the effects of the Dynamisch Beekdal project. In an almost contiguous strip of about 200 m wide, the Aa now meanders through the land, mostly in its original stream bed. There are also some cut off meanders present. Somewhat downstream of the castle, the brook Leijgraaf joins the Aa. Just before the Maxima Canal a new branch of the Aa, the Rosmalense Aa branches off from the Aa, and streams along the Maxima Canal to the Meuse. In three places, dykes are now situated at some distance from the river. These places can receive over a million m3 of water in case of emergency. There are some bridges exclusively for cyclists and pedestrians. No roads have been made along the Aa, so tourists walking along the water are not hindered by wheeled commuters. Canoeing is now a major recreational activity on the Aa. This stretch also has some cultural attractions. First of all Heeswijk Castle, which is the best known castle in North Brabant. Its position on the Aa, just upstream of 's-Hertogenbosch, explains why it was so important for such a long time. At the junction of the Aa is a building that remains from the medieval mill Ter Steen. Further downstream are the ruins of Seldensate Manor, which is often called a castle. It has a late medieval gate house, and the ruins are open to visitors. A ford over the Aa was located just north of Seldensate Manor. In 2017 many Roman coins of little value were found nearby over a larger area. It allowed archaeologist to conclude that the ford shown on a 1832 map, already existed in Roman Times.