"For extra scares, I recommend Auld Reekie Tours, which — like Mercat — offers vault and graveyard tours but also runs an adult-only nightly Terror Tour (suitable for 18+) that will definitely leave you wishing you had a nightlight; you can even book out the vaults for an overnight stay if you want an extra scare (it's not cheap but would be a memorable experience)." - Matthew Kepnes