Woodcarving, an ancient Turkish art, was employed in various techniques on architectural elements such as columns, doors, window shutters, and on objects such as Koran cabinets, chest boxes and small tables. As of the 17th century, tortoise shell, mother-of-pearl, ivory and bone appliqués became more popular. Exquisite examples of mother-of-pearl inlay work can be seen at Topkapı Palace, Mihrimah Mosque, Tomb of Murad II in the Ayasofya complex, Beylerbeyi Mosque and Sultan Ahmet Mosque (also known as Blue Mosque).