Our greatest window into the #universe is nearing completion. This soon-to-be #telescope is located at the top of Cerro #Armazones, the mountain that casts a triangular shadow. At 3046 metres above sea level, and with very dry conditions, the #ELT is in the perfect location for astronomical observations under one of the most pristine skies on Earth. Its dome, planned to be fully completed in 2027, protects the telescope and its sensitive components from the extreme desert environment, and from the Sun during daytime. At night, its two massive sliding doors will open to allow the telescope to observe the night sky, while still protecting it from the wind. #astronomy https://www.eso.org/public/images/potw2617a/