Today's abandoned mine exploration was in Leppävaara.
Not a particularly big mine, though, barely noticeable. A quarry rather, in the Leppävaara's Kaivoskallio (mine hill). There's several places where they've quarried iron ore in the 1800s. The largest hole is in coordinates N 60.22640 E 24.79614. I also found a small ~ two meter cave under a boulder at the top of the hill in coordinates N 60.22669 E 24.79586.
Views from the hill: