Vipava at Bilje (old mill weir)
The weir of an old mill at Bilje backs up the Vipava into a pool several kilometres long, up to 7 m deep in mid-channel. The gravel bed is littered with First World War remains, some of them still dangerous, and there are plenty of freshwater mussels and shoals of small fish. You can do a simple out-and-back from the mill or a longer drift of about 800 m from the sewage works down to the weir.
depth: 0–7 m