It is 42 kilometres (26 miles) long and begins in Westport and ends in Achill, passing through the towns of Newport and Mulranny as it runs along the coast of Clew Bay.

[6] The full route was opened by Taoiseach Enda Kenny, T. D. and Minister of State for Tourism and Sport, Michael Ring, T. D., on 29 July 2011.

[4] According to a 2013 study,[7] the Great Western Greenway had an average of 471 cycle trips per day, or 172,000 users in total per annum.

[citation needed] After reconstruction of part of the N59 at Kilbride,[8] and completed in September 2013, a section of the greenway that originally shared space on the road with cars and other traffic, is now safely segregated.

However, there remains a 1-mile (2-kilometre) section through Newport town where greenway users share road space with other traffic.