A group of telescopes at the Roque de los Muchachos Observatory on La Palma in the Canary Islands, jointly owned and operated by the UK, Netherlands, and Spain. As well as the 4.2-m William Herschel Telescope and the 2.5-m Isaac Newton Telescope, the group includes the 1-m Jacobus Kapteyn Telescope (JKT), opened in 1984. The headquarters of the group is at Santa Cruz on La Palma island.

http://www.ing.iac.es/ Official observatory website.