The Celestial-class Universal Star Destroyer was the biggest Star Destroyer ever built. From stem to stern it was 130,000 kilometers (approx. 80,000 miles). It could fit Sovereign and Eclipse-class Super Star Destroyers in one of its hangars. Instead of being in service to the Galactic Empire, it was in service to the Mandalorian Empire. It had a droid factory, which produced millions of droids each standard day. The gunners on the ship were said to have been so accurate that if a city was at the base of a mountain, the gunners could destroy the city without even singeing the grass on the mountain.