Workers clean empty cooking oil containers at a roadside recycling workshop in Kolkata, India, July 13, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A truck driver cleans the mirror of his decorated truck in Charsadda outside Peshawar, Pakistan October 18, 2016. (Photo by Fayaz Aziz/Reuters)

Workers install a monument inside Beirut port as a remembrance for the victims of the 04 August harbor blast in Beirut, Lebanon, 27 July 2021. A massive blast on 04 August 2020 rocked Beirut's port in which at least 200 people were killed and more than 6,000 injured, believed to have been caused by an estimated 2,750 tons of ammonium nitrate stored in a warehouse, devastated the port area of Beirut and several parts of the city. (Photo by Wael Hamzeh/EPA/EFE)

Two women react to the camera as Nightclub Circus hosts the first dance event, which will welcome 6,000 clubbers to the city's Bramley-Moore Dock warehouse on April 30, 2021 in Liverpool, England. The event is part of the national Events Research Programme which will provide data on how events could be permitted to safely reopen. (Photo by Anthony Devlin/Getty Images)

A child watches as an adult poses for a photograph while holding a Thompson AR-15 rifle, which is inscribed with the likeness of former US President Donald Trump at the Tommy Gun Warehouse during the annual Rod of Iron Freedom Festival in Greeley, Pennsylvania, 07 October 2023. The festival is one of the the largest open carry festivals celebrating the 2nd Amendment in North America. (Photo by Will Oliver/EPA)

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 schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

India: A sweeper cleans the side of a road near a replica of the Eiffel Tower amid heavy fog in the early morning in the northern Indian city of Chandigarh January 18, 2010. (Photo by Ajay Verma/Reuters)