National Cycle Route 8 (or NCR 8) is a route of the National Cycle Network, running from Cardiff to Holyhead. The route passes through the heart of Wales, and is also known as Lôn Las Cymru (Welsh for 'Wales' green lane'). It is largely north–south from Holyhead to Cardiff or Chepstow, and in total measures some 400 km (250 mi) in length. Some of its route follows the trackbed of former railway lines, such as Lôn Las Menai, Lôn Eifion, the Mawddach Trail and the Taff Trail; in other places, the route is on public highways.
Both ends are easily accessible via the rail network.