Mobotropolis (sometimes known as Old Mobotropolis) was the name of the first ever multi-cultural city on Mobius and the capital of the Kingdom of Acorn. It was originally created by a collective group of Mobians under the leadership of Alexander, the first King in the Acorn Dynasty. Centuries later, the city was captured during Dr. Ivo Robotnik's coup d'état and became the capital city of his global empire, rechristened Robotropolis. It was briefly reclaimed after Robotnik's apparent demise, but reclaimed by his successor, Dr. Eggman. Over eleven years later, the city was subsequently destroyed by a nuclear strike from Station Square, though the toxic radiation was contained within the city's dome shield.