Have you ever known a place to be "truly evil?"?

Last night a friend and I were talking about one place we knew mutually. She said the place was “evil, evil, evil” and so many people had been affected by that place. I do believe there are people who are inherently evil for one reason or another, but a place?
It made me wonder about what others might have experienced… have you experienced a place that you are convinced was truly evil, and what happened to make you believe this?