The Gibraltar 100 Pounds Banknote from 2011 is part of the 2010 2011 series. Its obverse side features a crenelated castle tower as a registration device, a portrait of Queen Elizabeth II, and the coat of arms of Gibraltar. The reverse side features the Kings Bastion from 1773 and a crenelated castle tower. The note is 163 x 90 mm in size and contains an Optiks security thread to enhance its security features. A watermark image of Queen Elizabeth II, electrotype 100, and Cornerstones are also made visible under a UV light.