Earth

Earth was a world on an alternate Material Plane.

People
A number of human peoples of Faerûn originally came from another world, which is widely believed to have been Earth. To replenish their population after a devastating plague, the mages of the Imaskar Empire in Faerûn opened two great gates to this other world, and kidnapped numerous humans to serve as their slaves. Those of Mulhorand hailed from a desert land given life by the seasonal flooding of a great river and those of Unther from another land. After transporting them back to Abeir-Toril, the Imaskari closed the gates forever. Intermarrying both with each other and the Imaskari, they became the Mulan. With them, they brought their own societies, mature culture, and later, the gods of the Mulhorandi and Untheric pantheons.

Later came a people from two lands: a collection of city-states known for their daring philosophies and a land of empire and glory; they had similar pantheons of gods. These were followed by folk from a rugged land with a culture tied to nature, the sea, and the warrior history of its dozen-king greater god. These brought their own societies and faiths, and settled around the time of the rise of Netheril.

In the Year of the Prince, 1357 DR, an inhabitant of Earth called Ed of the Greenwood assembled various journals, maps, and other works from Elminster Aumar into the first publication of the Forgotten Realms campaign setting.

Laeral Silverhand also regularly traveled to Earth to visit Steven E. Schend and spoke to him of Waterdeep, even if she did tend to interrupt his writing. He compiled the lore into articles for Dragon magazine.

Deities
A number of gods of Egyptian pantheon and the Babylonian and Sumerian pantheons of Earth traveled to Toril and formed the Mulhorandi and Untheric pantheons, respectively. The god Poseidon of the Greek pantheon also had a small following on Toril.

A number of animal spirits, foremost among them Eagle and Raven, were worshiped both by the green elves of Toril and the American Indian peoples of Earth.

Fauna
Foxes were never native to Toril, and were actually brought from France by an adventurous halfling trader named Altho Minstrelwish.

Locations
The Pecos River was a river on Earth. St. Sollars the Twice-Martyred described the demon lord Orcus, Prince of the Undead, as "the meanest dude this side o' the Pecos".

The wizard Elminster's favorite place to relax and find rest off Toril was found in Yellowstone National Park on Earth. He kept a magic portal there from his hideout within the planet Coliar, specifically to the Earth year 1894 AD. It was also here that he purchased German beer to sell to his friend Gamalon Idogyr.