**SUBSCRIBE TO OUR CHANNEL FOR MORE PORTAL** <br />Behind the scenes (17.36) @DMPortal - like us on facebook.com/portalondailymotion <br /> <br />Exclusive behind the scenes on the production of Portal, join Director Mark Ashmore and Co-producer Sarah-Lee Jones on a look back on the high and low points of making Portal - also tweet or facebook us and let us know what you think!