Son doong cave is a cave in Phong Nha-Kẻ Bàng National Park, Bố Trạch district, Quảng Bình Province, Vietnam. Currently the biggest known cave in the world, the cave is located near the Laos-Vietnam border. Inside is a large, fast-flowing underground river.
In early August 2013, the first tourist group explored the cave on a guided tour at a cost of US$3,000 each. The group had six members from Australia, Norway, Russia and USA and spent 7 days and 6 nights for the tour. Next exploration trips will be arranged.

Award-winning photographer Barry Lewis has been picturing the weird and wonderful late-night Glastonbury experience for more than a decade. Shangri-La is a festival of contemporary performing arts held each year at Glastonbury festival, and Barry Lewis has documented its denizens. Here: Spa in Slumbarave’s Hotel Metropolis, Shangri-La, Glastonbury, 2009. (Photo by Barry Lewis/The Guardian)

A woman dressed for la “La Diablada” festival, walks down a road in Pillaro, Ecuador, Friday, January 6, 2017. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Chinese tourists make a toast with canned drinks and fried chicken pieces during an event organized by a Chinese company at a park in Incheon, South Korea, March 28, 2016. (Photo by Kim Hong-Ji/Reuters)

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A young girl makes a “tomato angel” on a tomato covered street during the traditional tomato fight “Tomatina” during the fiestas in Bunol, Spain, 28 August 2013. This year's Tomatina is the first pay festival after Bunol's City Hall sold 15,000 tickets to take part in the tomato throwing. A total of 20,000 people, including 5,000 residents, will throw over 130,000 kg tomatoes. Local authorities decided to sell tickets this year to avoid the overcrowding in previous years in which over 50,000 people took part in the event. (Photo by Biel Alino/EPA)

Audrey Tautou attends “La Delicatesse” Paris Premiere on December 13, 2011 in Paris, France. (Photo by Pascal Le Segretain/Getty Images)