Derived from 16x16 indoor rpg tileset: the baseline
Art by Stephen Challener (Redshrike). Commissioned by OpenGameArt.org (http://opengameart.org)
http://opengameart.org/content/16x16-indoor-rpg-tileset-the-baseline
http://creativecommons.org/licenses/by/3.0/
http://opengameart.org/content/oga-by-30-faq