We set off by bike to several places in Oise, near...

We set off by bike to several places in Oise, near the Veolia water station, to reach the ponds of Cergy. By the towpath.
Unfortunately, we had to go out through a factory, drive and join the path further, at least 1 km. After no problem until the ponds. Walk 20 kms alley. I think that the factories which block the passage are outlawed. But as our elected officials have other things to do, we have time to spend a day by the towpath to the end.
Attention masks compulsory in the parks. 135 euros fine, even by bike.