Garda National Surveillance Unit

The National Surveillance Unit (NSU) (Irish: Aonad Faireacháin Náisiúinta) is the principal clandestine intelligence gathering and surveillance operations unit of the Garda Síochána, the national police force of Ireland. The unit operates under the Crime & Security Branch (CSB), based at Garda Headquarters in the Phoenix Park, Dublin, and also works from Harcourt Street, Dublin.