The Glamorganshire canal, opened in 1794, runs from Cardiff to Merthyr Tydfil, with a branch to Aberdare.
In 1798 the first dock (12 acres in extent) was constructed at the terminus of the Glamorgan canal from Merthyr.
eastwards there is a station on the Brecon and Merthyr railway at Bedwas.
In Great Britain there is the South Welsh field, extending westward from the march of Monmouth shire to Kidwelly, and northward to Merthyr Tydfil.
A branch from the main line at Tyn-y-caeau connects with the Rhymney railway, the London & North-Western railway, and the Brecon & Merthyr railway.