The City of Sigil is a central hub in the Dungeons & Dragons multiverse, known as the "City of Doors." It is a unique metropolis that connects to various planes of existence through numerous portals, allowing travelers to access different realms easily. The city is ruled by the enigmatic Lady of Pain, who maintains order and prevents any gods from entering. Sigil is characterized by its diverse population, including various races and creatures from across the multiverse. The city's architecture is eclectic, with buildings that defy the laws of physics. Its streets are bustling with merchants, adventurers, and scholars, making it a vibrant center for trade and knowledge.