Inprisoned Herring Gull

Whilst on a visit to Porthgain this afternoon we came across the bizarre sight of a poor Herring Gull trapped behind bars in the old brick factory there. It appears to have slid down the steep bank behind it and is not able to get back up due to the thick vegetation. Bloodstains on its flank suggest it has been trying to get out through the iron bars but that would be impossible! Would anybody know of a local wildlife rescue organisation which may be able to help release it from prison? Assuming it is unable to get back up the bank this bird will inevitably become very distressed and probably die.