Ruin spaces are already drawn on each players Map sheet and have 2 columns depicting them.
Ruin spaces are counted as empty spaces until a Terrain is drawn on top of it.
Players can draw over Ruins spaces any time they need to draw a new Shape.
However, after a Ruins Card is revealed, players MUST draw the next Shape over a free Ruins space if possible.
If players can't draw the required Shape over a Ruins space after revealing a Ruins card, then they MUST instead draw a 1x1 square and fill it with ANY Terrain type (excluding Mountains).