The clog [Dutch klomp (singular), klompen (plural)], a wooden shoe that covers the whole foot, is a well-known part of Dutch costume though they were only worn for rough outdoor work and would never have been worn with festive clothing or indoors. Originally, clogs were meant to be worn alone or over cloth or leather shoes.
Clogs are made from wood and the earliest surviving examples in Europe are from Amsterdam and Rotterdam in the Netherlands, and are dated from the 13th century. These finds look very similar to the wooden shoes that are still worn in The Netherlands today. However, wooden footwear is known throughout the world, though its shape and form vary greatly.
Klompen can be made from willow or poplar wood. Traditionally, they are hand-carved, plain and unpainted. They were perfect footwear for the marshy lowlands that comprised much of the Netherlands. The name of this country means the “lower countries” and only 50% of the land is more than 1 metre above sea level.
Approximately 3 million pairs of klompen are made each year for sale in the Netherlands. A large part is for the tourist souvenir market, though some Dutch farmers, market gardeners, and gardeners still wear them for everyday use as they are accredited safety shoes and can withstand almost any penetration including sharp objects and concentrated acids. They are actually safer than steel-capped protective shoes in some circumstances, as the wood cracks rather than dents in extreme accidents, allowing easy removal of the clog and do not induce the continued pressure on the toes caused by the steel cap.
The secret to wearing the hard wooden klompen lies in the thick woollen socks that Dutch women knit to keep the feet warm, dry and free from chafing. Originally, clogs were meant to be worn alone or over cloth or leather shoes.
Condra Jill (2013) Encyclopedia of National dress. Traditional clothing around the world. Volume 2.ISBN 978-0313-37635-8