A real one this time, with fewer smoke monsters and a lot more tourists: Alcatraz!
Doesn't sound sf/f, but it might have light genre elements.
Alcatraz is described as "a show about mysteries, secrets and the most infamous prison of all time: Alcatraz."
Is it going to be a historical drama set when the prison was running, or a contemporary drama about the island as a national monument? If the latter, they'll definitely have to amp up the ghostly balderdash.
It's not a very big island and frankly my dears, it's not even very interesting. The best thing about it is the incredible views since you're right in the middle of the bay. I think they should just bulldoze those crumbling, ugly-ass buildings and turn it into a lovely park but I know they make boatloads of money from tourists so forget about that.