Conservator's discuss a 12th century piece of stained glass during restoration work at York Minister in York, northern England December 13, 2011.The east end of the Minister is undergoing a 20 million pounds ($31 million) restoration, which includes the East Window, designed by John Thornton in 15th Century. The project is expected to be completed in 2016. Photograph taken on December 13, 2011.[Photo/Agencies]