The International Day against Nuclear Tests is observed on August 29 to highlight the harmful effects of nuclear testing and push for an end to it. The UN General Assembly designated the day in 2009 and it was first marked in 2010. It commemorates the closure of the Semipalatinsk Nuclear Test Site in Kazakhstan on August 29, 1991. The Comprehensive Nuclear-Test-Ban Treaty (CTBT), adopted in 1996 to end all nuclear tests, has still not entered into force.