Alternating rice plots in the Bac Son Valley, Vietnam. Photographed by Hai Thinh Hoang, of Hanoi. #

Grandpa's helper, for the Americana category, photographed by Jenny Braun in Hampton, Minnesota, in July of 2012. #

Ants holding seeds, by Eko Adiyanto, of West Java, Indonesia. #

Lone Acacia, Sossusvlei Sand Dunes, Namibia. Photographed by Bob Bush of Altadena, California, in May of 2010. #

A visit to Bagan, Myanmar in January of 2011. Photographed by Han Tha, from Yangon, Myanmar. #

Musicians arriving at the bullring in Quito, Ecuador, in October of 2011. Taken by Raul Amaru Linares, of Bogota, Colombia, for the Travel category. #

A man-made ice geyser in Duluth, Minnesota. Taken in December, 2011 by Nathan Carlsen, of Duluth. #

Blues in the streets of Chicago, by Javier Arcenillas of Alcobendas, Madrid, Spain, for the American Experience category. #

The awesome power of an Iowa tornado, in Mapleton, Iowa. Photographed by Timothy Wright of Omaha, Nebraska. #

Rice Terraces Close to Harvest Season, in La Pan Tan, Mu Cang Chay, Yen Bai, Vietnam. Taken by Vo Anh Kiet of Ho Chi Minh City. #

Policemen run across the National Congress in Brasilia during a demonstration against corruption. Photographed by Olivier Boels from Brasilia, Brazil. #

Il Duomo di Firenze, by Garret Suhrie of Los Angeles, California. Submitted in the Altered Images category. #

Apple Guy on location in the desert, by Ron Henderson of Dallas, Texas. #

Annual bucking horse sale in Miles City, Montana. Photographed by George Burgin, of Billings, Montana. #

River ferry operating in the early morning in Xiao Donjiang, China, by Teng Hin Khoo, of Shah Alam, Malaysia. #

People harvesting salt at sunset by Giang Hai Hoang of Hanoi, Vietnam. Photographed in August of 2012 in Khanh Hoa Province, Vietnam. #

Breeding penguins in Antarctica in February of 2012, by Neal Piper, from Washington, District of Columbia, #