Lierelva is a river located in Norway, flowing through the municipality of Lier in Viken county. It is approximately 20 kilometers long and is known for its scenic beauty and natural surroundings. The river is a popular spot for outdoor activities such as fishing, hiking, and kayaking. The river originates from the Lier Valley and eventually flows into the Drammenselva river system. Lierelva plays an important role in the local ecosystem, supporting various wildlife and plant species. Its banks are lined with lush vegetation, making it a vital habitat for birds and other animals.