Boat trips were one of the popular attractions at an open day at Denver Sluice.
An estimated 300 to 350 people went along to the event on Tuesday to look around the complex along with learning about wildlife in the area.
The open day was put on by the Environment Agency and the Ouse Washes Landscape Partnership as part of a fortnight of events to showcase the area’s unique landscape.
Visitors learned more about the local wildlife with help from Norfolk Wildlife Trust and the RSPB.
Children also had chance to pick up a crayfish, which is one of the invasive species on in the Environment Agency’s eel and fish tanks.
There were also interactive games and activities organised by the Norfolk Non-native Species Initiative for youngsters.
Ely Hereward Rotary Club were at the open day with their interactive cycle ride.
The Littleport Field Theatre Group invited visitors to experience their catching, cooking and eating of eels installation.
Children and their families enjoyed dressing up in traditional costumes which were brought along by the Rosmini Centre, in Wisbech.
Visitors also learned more about Denver Sluice with tours by site superintendent Dan Pollard.
Weather affected Cambridge Archaeological Unit’s demonstration of the mid-19th century Flat Earth Trials experiment.
But a popular attraction was the boat trips with river inspector Mervyn Day.
Amy Tillson, part of the team at the Ouse Washes Landscape Partnership, said: “The event itself closed at 4pm but people were still queuing beyond that for the river trips. Mr Day ensured everyone got a trip out.
“It was a really successful day and we want to make it bigger and even better next year.”
There are still a host of events being held as part of the OuseFest, including an archaeological dig in Hilgay.
For more go to www.ousewashes.org.uk/ousefest