Guests on the terrace of Shepheard's Hotel, Cairo, circa 1940. (Photo by Hulton Archive/Getty Images)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.

“Solar Impulse is a European long-range solar powered plane project being undertaken by Bertrand Piccard and André Borschberg. The project eventually hopes to succeed in the first circling of the earth with a piloted fixed-wing aircraft using only solar power. The first aircraft, bearing the Swiss aircraft registration code of HB-SIA, is a single-seater, capable of taking off under its own power, and intended to remain airborne up to 36 hours. This aircraft first flew an entire diurnal solar cycle, including nearly 9 hours of night flying, in a 26-hour flight on 7–8 July 2010”. – Wikipedia


Photo: Workers prepare the Solar Impulse airplane HB-SIA for a first runway test on November 19, 2009 in Dubendorf, Switzerland. Solar Impulse chairman Bertrand Piccard, psychatrist and aeronaut, who made the first non-stop round-the-world balloon flight, and CEO and former fighter pilot Andrй Borschberg plan a round-the-world flight, driven only by solar energy, for 2012. (Photo by Johannes Simon/Getty Images)

A visitor takes a picture of a display bearing hand prints of war heroes from the War of Resistance against Japan, at Jianchuan Museum Cluster in Anren, Sichuan Province, China, May 13, 2016. Tucked away in southwestern China's Sichuan province, a private collector stands virtually alone in exhibiting relics from the 1966-1976 Cultural Revolution. Monday marks the 50th anniversary of the start of the political movement, with no official commemorations planned. Official records whitewash the details of both periods, but admit that Mao made major mistakes. (Photo by Kim Kyung-Hoon/Reuters)

Cooperation is key to success. This motto was used by the Government of Denmark when they decided to create a project that bore the name of UN City. This compound was designed to house all nine Copenhagen based UN agencies under a single roof. This embodies the core idea of the United Nations, since this project allows for better efficiency and practicality thanks to joint effort. The first plans for the UN City were hatched in 2002. After 11 years, in 2013 the first stage of the project was finally finished. Presently, Campus 1 of UN City accommodates 1,300 staff member, while Campus 2 is going to become the largest humanitarian warehouse in the whole world.

A boy looks for sellable materials close to the burning garbage in the permanent waste land under Sylhet City Corporation for a living, on January 15, 2015. (Photo by Md. Akhlas Uddin/Pacific Press)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)