A 13th-century fresco rediscovered in Ferrara, Italy, provides unique evidence of medieval churches using Islamic tents to conceal their high altars. The 700-year-old fresco is thought to be the only surviving image of its kind, offering precious evidence of a little-known Christian practice. A 13th-century fresco rediscovered in Ferrara, Italy, provides unique evidence of medieval churches using Islamic tents to conceal their high altars. The 700-year-old fresco is thought to be the only surviving image of its kind, offering precious evidence of a little-known Christian practice. Archaeology Phys.org – latest science and technology news stories