Luray Caverns
Have you ever visited a cavern? In Midnight in the Garden with Eros John and Diana visit a local cavern together, but I won't tell you what happens there, that would be a spoiler. However, I will say that my inspiration came from several of the caverns I have been lucky enough to visit over the years. In the UK as a child I visited the Blue John Cavern in the Peak District, it seemed like a miraculous place to me as a small child! It is most famous for the Blue John stones that are mined there and used to make jewelry and small objet d'art. Here's a link if you'd like to check it out. Blue John Cavern or https://www.bluejohn-cavern.co.uk/
In the US when I lived in Virginia I was lucky to visit the Luray Caverns, the largest on the east coast, it was one of the things I was determined to do before we left the State and it was well worth the visit, they also have a car and carriage museum and a small toy museum, fabulous for us history lovers! Here's the link: Luray Caverns or https://luraycaverns.com/