It makes me feel small and completely defenseless. Any kind of open area that feels still, or dead... like, a field won't do it for me. Theres hills and breeze and other things that remind me this is a natural place. But if I'm in an empty stadium or underground car park, I get this paranoia that I'm being watched and if whatever was watching decided to come for me, I'd never be able to outrun it.
Space gives me the same feeling... huge, still, dead, infinitely imposing.