Huh. Yeah, that's weird. Maybe it's older.

[He moves towards an ancient tree that spreads its thick limbs high over the dead and leans back against its trunk, arms crossed.]

That happens sometimes, right? A town or city comes up where there was something else before. Craters turn into seas; big ice caps melt and people build on the new land that was hidden underneath. [He nods at the graves.] This could be something like that.