A couple embrace during the start of the San Fermin festival in Pamplona, Spain July 6, 2016. Revelers from around the world kick off the festival with a messy party in the Pamplona town square, one day before the first of eight days of the running of the bulls. (Photo by Vincent West/Reuters)

A barn painted with the U.S. flag is seen in the snow covered field in Kanawha, Iowa, United States, January 16, 2016. Iowa will be the first state to hold its primary, with both Democratic and Republican events being held February 1, 2016. (Photo by Jim Young/Reuters)

Women dressed up as Vikings attend the annual Viking festival of Catoira in north-western Spain on August 5, 2018. The festival re-enacts past Viking raids in the area and is celebrated annually on the first Sunday of August. (Photo by Miguel Vidal/Reuters)

Takehiko Yagi is a rising star in Japanese photography, and his vibrant pictures of the Hindu spring festival of Holi won the Grand Prize at the fourth annual Nikkei National Geographic Photo Prize. Diving into the Colors of Holi is his first exhibition in the US, on show at Foto Care Gallery in New York until 28 September, 2016. Here: Jaipur, India, 2013, (Photo by Takehiko Yagi/The Guardian)

Russian participants adjust their hair, preparing for the Kremlin Cadet Ball in Moscow, Russia, 08 December 2016. Pupils of cadet schools from different parts in Russia gathered for the first Kremlin Ball, restoring an old tradition of Russian officers and noble girls. (Photo by Sergei Chirikov/EPA)

To commemorate the centennial of Britain’s involvement in the First World War, ceramic artist Paul Cummins and stage designer Tom Piper conceived of a staggering installation of ceramic poppies planted in the famous dry moat around the Tower of London. Titled “Blood Swept Lands and Seas of Red,” the final work will consist of 888,246 red ceramic flowers—each representing a British or Colonial military fatality—that flow through grounds around the tower.

School girls stand next to a ballot box at a polling station during the municipal elections in Havana April 19, 2015. Cuba held its first local elections since a historic thaw in relations with the United States with an unusual wrinkle in the single-party system: two of the 27,000 candidates openly oppose the government. (Photo by Reuters/Stringer)

Participants dance during the West Indian Day Parade in the Brooklyn borough of New York September 5, 2016. The Labor Day Carnival (or West Indian Carnival) is an annual celebration held on American Labor Day (the first Monday in September) in Crown Heights, Brooklyn, in New York City. (Photo by Eric Thayer/Reuters)