aerial photograph ofSwan Lane Mills, Bolton Greater Manchester UK. Built in two stages in 1902 and 1905 with No 3 Mill ( behind ) added in 1915. In 1905 this was the largest cotton mill in the world. The Cotton Mill was intended to house 210,000 mule spindles powered by a 1300hp cross compound steam engine. Today the mills are used for a variety of purposes and are Grade II listed.