The Blue Man Group performs on stage during a media preview ahead of their show in Singapore on March 31, 2016. Blue Man Group was started by three friends in New York in 1991 as a way to celebrate the human spirit through music, science, art and theater. (Photo by Roslan Rahman/AFP Photo)

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.

Floralis Genérica is a sculpture made of steel and aluminum located in Plaza de las Naciones Unidas, Avenida Figueroa Alcorta, Buenos Aires, a gift to the city by the Argentine architect Eduardo Catalano. Catalano once said that the flower "is a synthesis of all the flowers and is both a hope that is reborn every day to open." It was created in 2002. The sculpture moves closing its petals in the evening and opening them in the morning, although this mechanism is currently disabled. The sculpture is located in the center of a park of four acres of wooded boundaries, surrounded by paths that get closer and provide different perspectives of the monument, and placed above a reflecting pool, which apart from fulfilling its aesthetic function, protects it. It represents a large flower made of stainless steel with aluminum skeleton and reinforced concrete, which looks at the sky, extending to it its six petals. Weighs eighteen tons and is 23 meters high.

These amazing pieces of artwork from a series called “TaxCut” have been created entirely out of money. Chad Person an artist from California created these collages from hundreds of tiny pieces of American dollar bills. Photo: Kraken. (Photo by Chad Person/Caters News)

Festival goers plays in mud during the 15th Annual Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 15, 2012. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisation. (Photo by Chung Sung-Jun)

A hen, a dog and a rabbit playing cards, circa 1956. (Photo by Evans/Three Lions)

A six-day-old hippopotamus is pictured next to his mother, Kara, aged 21, on September 12, 2012 at “Planet sauvage” (“Wild planet”) Zoo in Port-Saint-Pere, western France. The birth, a rare event for this species in captivity, occured on September 7, 2012 in the Zoo. (Photo by Frank Perry/AFP Photo)

Construction continues on One World Trade Center (TALLEST BUILDING AT LOWER LEFT) as the memorial footprints of the twin towers are seen (BOTTOM C) on August 12, 2011 in New York City. Upon completion, One World Trade Center will be New York's tallest skyscraper, topping out at a symbolic 1,776 feet, with 3 million square feet of office space. More than 2,700 people were killed when al-Qaeda terrorists hijacked U.S. passenger jets and flew them into the twin towers of the World Trade Center on September 11, 2001. Nearly ten years after the crippling attacks on Lower Manhattan, business, tourism and new construction like One World Trade Center have rejuvenated the formerly devastated cityscape.(Photo by Mario Tama/Getty Images)