Isaac Newton Telescope
![](/Images/godic/202501/21/Isaac_Newton_Telescope,_La_Palma,_Spain2550.jpg")
![](/Images/godic/202501/21/Herstmonceux_trig_with_Isaac_Newton_telescope_-_geograph.org.uk_-_677652550.jpg")
![Isaac Newton Telescope Mirror, with the primary mirror cover petals almost closed.](/Images/godic/202501/21/Isaac_Newton_Telescope_main_mirror2550.jpg")
![International Year of Astronomy commemorative coin featuring the Isaac Newton Telescope.](/Images/godic/202501/21/2009_Austria_25_Euro_Year_of_Astronomy_Front2550.jpg")
The Isaac Newton Telescope or INT is a 2.54 m (100 in.) optical telescope run by the ING at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984.
Originally it was situated at Herstmonceux Castle in Sussex, England, which was the site of the Royal Greenwich Observatory after it moved away from Greenwich due to light pollution. It was inaugurated in 1967 by Queen Elizabeth II. The telescope is now one member of the Isaac Newton Group of Telescopes.