And humbling, in a way, if I had to add to that.

Exactly. Maybe it's because we know our ancestors are buried there?

Well, if we're going to hunt for purely psychological reasons, i'd attribute the eerie peace and sense of humility as manifestations of how foreign death is to us as human beings, and anything mortal for that matter. We only remember the time we've been alive, we know nothing else in the same way we've come to know this world. So in a way, stepping into a cemetery is somewhat like stepping into the crossroads between this world and something else entirely that we really have very little understanding of as a whole.

Interesting... They also prepare us for death too.