Elfheim, also known as Elfland (エルフの国 Erufu-no Kuni "elf-country"), is a town in the original Final Fantasy. Located southwest of Cornelia, it is the home of the elves.
The prince of the elves is put into a deep sleep by Astos, the king of the dark elves. As the Warriors of Light, the party is asked by the kingdom of Elfheim for their help in order to defeat Astos. After they defeat Astos at the Western Keep and get an herb from Matoya to awaken the prince, he responds by giving them the Mystic Key, allowing them to get the explosives from Cornelia to give to the Dwarves.
The Background Music that plays in Elfheim is Final Fantasy's "Town" Theme.
Elfheim may be named after Álfheimr, one of the nine worlds that is inhabited by elves in Norse mythology.
In the GBA, PS1, and PSP versions, the left gravestone in Elfheim reads "Here Lies Link". This is a reference to Nintendo's The Legend of Zelda, as Link has an Elf-like appearance. This may very well be a stab at Nintendo, with Square-Enix (then Square)'s flagship series featuring the lead character of Nintendo's flagship series, The Legend of Zelda, as dead.
In the NES version of the game, the aforementioned tombstone instead says "Here lies Erdick", a reference to a character in the Dragon Quest series.
All the elves have a striking resemblance to Link from The Legend of Zelda as they wear green tunics, green hats, and have yellow hair.
The name "Elfheim" is most likely based off of the name "Alfheim" which, in Norse Mythology, was one of the Nine Worlds of The World Ash Tree and was inhabitated by the race of light elves.