The Aberdare branch serves Penrhiwceiber, Mountain Ash, Fernhill, Cwmbach and Aberdare. The line continues beyond Aberdare – for goods purposes only – to serve Tower Colliery, which was the last deep coal mine to remain open in South Wales. Mountain Ash station was redeveloped with a grant from the Welsh Assembly Government in the early part of the decade, the scheme including the provision of a new station and a passing loop to permit an upgrade of the passenger service to two trains per hour from late 2003. There are a few gaps in the half-hourly service to enable coal/stone trains to run to/from Tower Colliery/Hirwaun.