English: ESO's New Technology Telescope at La Silla is unique in that it can observe very low on the horizon. The telescope is not housed in a traditional dome with a slot in the roof to look at the sky, but in an innovative enclosure design with a sliding roof and wall that open up to leave a view of the sky which goes all the way to the ground. The whole building then rotates with the telescope to track objects on the sky. Inside the building the telescope can swing up or down, and was built to be able to swing down far further than normal telescopes: the NTT can point at objects only 10 degrees above the horizon.