The Lagan Valley (Irish: Cluain an Lagáin, Ulster Scots: Glen Lagan) is an area of Northern Ireland between Belfast and Lisburn. The Lagan is a famous river that flows into Belfast Lough. For a section, the river forms part of the border between the counties of Antrim and Down.
It has a number of interesting features including a towpath which runs alongside the River Lagan. The towpath is popular with walkers, runners, cyclists, dog owners etc. It is a very scenic and peaceful area and is ideal for walking, cycling etc. The towpath begins in the Stranmillis area of south Belfast and runs all the way to Lisburn. The cycle route forms part of National Cycle Route 9.There are a number of "off route" mountain bike trails along the towpath.
The parliamentary constituency has been a Unionist stronghold. The current MP for the constituency is Jeffrey Donaldson of the Democratic Unionist Party who was first elected as an Ulster Unionist Party candidate in 1997, retaining the seat in 2001. Following his defection to the DUP he retained the seat in 2005.