Rulebookp. 58
Closest
When a rule or effect refers to the closest hex, feature, or token, it means the route to that feature or token that consists of the fewest hexes between that feature and the component being measured to (or from).
When a rule or effect refers to the closest hex, feature, or token, it means the route to that feature or token that consists of the fewest hexes between that feature and the component being measured to (or from).