In November 2004, the United Nations Security Council held a rare session at Nairobi to discuss the take over of southern and western Sudan. The meeting was convened at the urging of then-Ambassador John Danforth of the United States.
UNON hosts the annual East Africa Model United Nations Conference for secondary school and University students from East Africa.
The UN Complex at Gigiri contains a 'green' building, a completely energy and carbon-neutral building, housing UNEP and UN-Habitat offices. The building is the first of its kind in Africa, recycling water and using natural light to reduce reliance on artificial lighting. In addition, the building is designed to use natural flow of air as a substitute to air conditioning, and it contains solar panels to generate all the energy that the building would consume. It was opened on 31 March 2011 by former UN Secretary-General Ban Ki-Moon and Kenya's former president Mwai Kibaki.