The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans nuclear explosions by everyone, everywhere: on the Earth’s surface, in the atmosphere, underwater and underground. Since the Treaty is not yet in force, the organization is called the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). It was founded in 1996, has over 260 staff from over 70 countries, and is based in Vienna. (Source: www.ctbto.org/)