Opened :1879

Closed : 1964

Engineering code : MTA

Length: 900m

Morlais Tunnel allowed the extension of the L&NW Heads of the Valleys route to join the Brecon and Merthyr Railway route north of Merthyr. The rest of the north Merthyr loop to Merthyr High Street station was shared between the companies. This twin-track tunnel ran from Pant to Morlais Junction. The tunnel has three shafts, and has a maximum depth of 80 ft. It is accessible from both ends, although the west portal is partly flooded. There are also a number of abandoned cars in the tunnel.