If I won that kind of money I’d definitely plough money into the local area, especially the Gurnos estate where I grew up. Sadly the old community centre where I spent most of my school holidays as a child / early teen is now a nursery / daycare centre.
I’d pay to fund to some local football clubs, especially junior teams from the deprived areas.
I’d invest some money into Merthyr Town. I’m now a part owner of the club after buying a season ticket and ownership card this season.