Indeed, this resort seems to be stuck in time, yes, you can get from Bucharest to Băile Herculane in two ways, the first way is by car, I think it's about 390-400 kilometers (you can do that in about 4-5 hours) and the second way is by train, which from what I know takes a little over 8 hours.

The location is quite far from the Romanian capital and it takes quite a while to get there.

I hope I was able to help you, if I can help you with anything else, write to me.