The 20 acre lake was drained towards the end of the 19th century. A 200 year old bridge spanned the Serpentine Lake. Over many years, this elegant structure fell into disrepair and has been completely rebuilt by Durham County Council using a combination of the original and new stone. In 1995 a Civic Trust Commendation was awarded for this sympathetic restoration. A nature trail runs through the marsh or fen-carr which was the original bed of the ornamental lake.
Interpretative panels indicate the stages of succession from wetland to woodland.
As you follow the trail you will see a variety of plant, insect and bird life. The trail has been designed to introduce visitors to the huge variety of trees growing in the Country Park. Many of these were planted during the 18th century by James Paine. The more unusual trees were planted in the early 1970s as part of a programme to develop the arboretum. The trail itself is located in the south western part of the park, around the lakeside and Temple Field areas.