Complex sentence: Bryn used to have a railway line in use with the coal mine, a tunnel named "Cwmcerwin Tunnel" which runs through to Maesteg still exists but was bricked up in 1989.The tunnel is 1012 yds long.
Split into simpler sentences: Bryn used to have a railway line in use with the coal mine, a tunnel named "Cwmcerwin Tunnel" which runs through to Maesteg. It still exists but was bricked up in 1989.The tunnel is 1012 yds long.