A boy carries a dog as he stands after a Peruvian police operation to destroy illegal gold mining camps in a zone known as Mega 14, in the southern Amazon region of Madre de Dios July 14, 2015. Peruvian police razed dozens of illegal gold mining camps at the edge of an Amazonian nature reserve this week, part of a renewed bid to halt the spread of wildcatting in a remote rainforest region. (Photo by Janine Costa/Reuters)

Britain's Chris Froome, wearing the overall leader's yellow jersey, is followed by Spain's Alberto Losada, Italy's Vincenzo Nibali and Spain's Alejandro Valverde as they speed downhill during the seventeenth stage of the Tour de France cycling race over 161 kilometers (100 miles) with start in Digne-les-Bains and finish in Pra Loup, France, Wednesday, July 22, 2015. (Photo by Christophe Ena/AP Photo)

Soldiers stand guard in Maua square where a cotton candy vendor passes by in Rio de Janeiro, Brazil, Saturday, July 9, 2016, as security is deployed to get to know the areas they'll be patrolling during the Olympics. Roughly twice the security contingent at the London Olympics will be deployed during the August games in Rio, which are expected to draw thousands of foreigners to a city where armed muggings, stray bullets and turf wars between heavily armed drug gangs are routine. (Photo by Leo Correa/AP Photo)

Members of the Paraguay-African cultural group Kamba Cua dance during celebrations in honor of Saint Balthazar, one of the Three Kings, on Epiphany in Fernando de la Mora, Paraguay, late Saturday, January 8, 2022, just days after the official holiday. The annual procession is a tradition that keeps Paraguay's Afro-descendants connected with their African roots through ancestral dance, drumming and customs. (Photo by Jorge Saenz/AP Photo)

Papier-mache sculptures, also known as “ninots”, burn during the “Nit de la Crema” (Fire Night) of the Fallas Festival in Valencia, eastern Spain, 19 March 2024. Fallas is a fortnight-long fiesta in which installations of parodic papier-mache, cardboard, and wooden sculptures are traditionally burnt every year on the last day of the event in the so-called “Crema” to end the festivities. (Photo by Biel Alino/EPA/EFE)

Costume details featuring Joao Candido, a black sailor who led a revolt against the physical punishment of Brazilian Navy soldiers at the beginning of the 20th century, lie inside the Paraíso do Tuiuti Samba school at the Samba City complex in Rio de Janeiro, Brazil, Tuesday, January 16, 2024. Samba schools are gearing up for this year's Carnival, scheduled from Feb. 9-17. (Photo by Bruna Prado/AP Photo)

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

Bryan Berg was introduced to card-stacking by his grandfather at the age of 8. He is a self-taught artist in all of the techniques he uses today. Berg's freestanding card structures are based on a grid-like arrangement, which Berg tested in a structural engineering lab to support 660 lbs per square foot―using no tape, no glue, no folding, and no tricks.