Merthyr Tydfil wants to see its industrial past recognised as world class by the United Nations heritage body Unesco.
The council is to put Cyfarthfa Heritage Area on Unesco's list of sites bidding for global classification.
World Heritage Sites are chosen for their outstanding universal value to culture, history or science.
Currently Wales has three World Heritage Sites: the castles and town walls of King Edward, in Gwynedd, the Blaenavon industrial landscape, in Blaenau Gwent, and the Pontcysyllte Aqueduct and Canal, in Wrexham.
