Location on Roadtrippers is slightly off, correct address is on Atlas Obscura. Has a fence with "no trespassing" signs but fence ends for those willing to go anyway, super cool and worth the trip even if you don't want to go past the fence.
This place is worth going out of your way to visit! First of all, once you enter the town on Dansville and look towards the mountains you'll see the beautiful building looming in the forest. Once you go onto Health St. you'll notice many, and I mean MANY, signs stating "private property do not enter", though we had no issues on our visit. There will be a blocked off road heading straight to Sanatorium, we parked a little ways off and traveled up the hill. It's a BEAUTIFUL sight. Travel around the back of the place and there will be a huge hole so you can enter and explore each and every floor of this building. We didn't venture into the basement but I can imagine that'd be a cool sight. There was also other buildings around in which we didn't have time to explore. You could make a day out of exploring this place!
This cemetery is b-e-a-u-t-i-f-u-l and goes on forever, head into the woods and there a long road with branches going to open patches with graves don't worry about not being able to get in we just went around a road block and no one seemed to care. Only thing to worry about is that the cemetery is not in the "best part" of Philly but we had no issues. Worth a visit :)
We drove all around this railroad, we were able to drive underneath the bridge which was pretty though we could not find a way in, I suggest to not go out of your way to see it, though it'd be cool to try if you're able