Wikipedia
Eidgah or Idgah is the term used in south Asian Islamic culture for the open-air gathering place usually outside the city (or at the outskirts) to perform the Salat al Eid (Eid prayers) for Eid ul-Fitr and Eid al-Adha. It is usually a public place that isn't used as a mosque at other times of the year. At the end of the holy month of Ramadan, Muslims celebrate by first offering prayers at an Eidgah. It is a large open ground for people to assemble and offer their prayers early in the morning on the Eid day. Although the term eidgah is of South Asian origin, Muslims around the world generally perform Eid prayers on similar pieces of open ground.
It was a practice of [[Muhammadﷺ]
] to perform the Eid salaah (prayer) in an open space on the outskirts of the city. Hence, it is considered a sunnah to perform Eid salaah at the Eidgah. The very first Eidgah was at the outskirts of Medina nearly 1,000 footsteps from Masjid al Nabawi.