Artist Ted Harrison makes final adjustments to his artwork created with poppies on the floor of St. Paul's Cathedral on November 10, 2011 in London, England. Mr. Harrison created the work on a 30 foot disc under the main dome of the cathedral with the intention of drawing attention to the 250,000 children worldwide currently under military orders. (Photo by Peter Macdiarmid/Getty Images)

Chinese Artist Ai Weiwei holds some seeds from his Unilever Installation “Sunflower Seeds” at The Tate Modern on October 11, 2010 in London, England. The sculptural installation comprises 100 million handmade porcelain replica sunflower seeds. (Photo by Peter Macdiarmid/Getty Images)

An authenticated contemporary copy of Leonardo da Vinci's Mona Lisa on display at the Prado Museum on February 1, 2012 in Madrid, Spain. Experts of the Prado Museum say the copy was painted at the same time as the Mona Lisa in Leonardo Da Vinci's studio by one of his students.

Birds made of recycled tires are displayed in a shop located on the Panamerican highway near Catarina town, May 7, 2015. Salazar recycles used tyres to make bird figurines and sofas to sell in his shop located on the Panamerican highway. (Photo by Oswaldo Rivas/Reuters)

Artist Paolo Curcio craves tiny bas-relief sculptures into coins – a traditional art form known as the hobo nickel. Curcio’s coins feature intricately detailed hobos, skulls and a variety of pop culture characters. Plastic castings of his works are available online.

California-based photographer Seth Casteel made his name taking photographs of dogs underwater, but before that, he was snapping cats on land.