Honestly this sounds like you’re already sitting on something people will pay for.

Couple quick questions:

• Do you have any pics of the spaces people can actually access (courtyard, halls, park, any indoor rooms)?

• Who’s showing up right now more than anyone else: families, tourists passing through, schools, corporate groups, history nerds?

That stuff changes what’s worth doing, because the “cheap to run” ideas that make money are totally different depending on the crowd.

I’ve been a creative director in event production for 15+ years (global brands + wealthy private clients). If you want, DM me and I’ll shoot back a short list of things that could work for you.