(Cherenkov Telescope Array) The first telescope on a Cherenkov Telescope Array (CTA) site is being inaugurated on 10 October. The prototype Large-Sized Telescope is intended to become the first of four LSTs on the north site of the CTA Observatory. More than 200 guests from around the world will gather to celebrate this occasion at the site of the prototype on the Roque de los Muchachos Observatory on the island of La Palma.