A small marked place. Also to notice — the same word for a location and for finding one.
Old English splott (a spot, a small patch of ground), of uncertain further origin; the sense of noticing grew from the mark itself, since to spot something is to pick out its mark.
A small marked place, and the act of noticing one. The same word serves the location and the act of finding it, because a spot is only a spot once it has been picked out.