A "no-go area" or "no-go zone" is a neighborhood or other geographic area where some or all outsiders are either physically prevented from entering or can enter at risk. The term includes exclusion zones, which are areas that are officially kept off-limits by the government, such as border zones and military exclusion zones. It also includes areas held by violent non-state actors, such as guerillas/insurgents, organized crime and terrorist organizations. In some cases, these areas have been held by insurgent organizations attempting to topple the government, such as Free Derry, an area in Northern Ireland that was held by the Irish Republican Army from 1969 to 1972. In other cases, the areas simply coexist alongside the state; an example is Kowloon Walled City, an area in Hong Kong essentially ruled by triad organizations from the 1950s to the 1970s.