It will only take an hour or so, to go around the Museum and the outside exhibits. So only pay for an hours parking.
I have managed to make arrangement to visit Great Western Colliery / Hetty Pit in the afternoon.
If there is time we can go across the road to Lewis Merthyr Colliery. Now know as Rhondda Heritage Park.
Access at Great Western is a little tricky. Up a flight of steps, but Matty has willingly volunteered to carry me up there.
Google:
Great Western Colliery
and
Rhondda Heritage Park
And you will know as much as me. Maybe more 😮
Cutting coal in my spare time.