Rivendell

"Imladris"
Imladris, Rivendell, or the land between the rivers is another sanctuary of the elves. Created by Lord Elrond using his ring of power, Vilya, after the destruction of Eregion, it prospered in both smith-work and agriculturally. Rivendell is also home to many important relic, these include: the shards of Narsil, the Sceptre of Annúminas, the Star of Elendil, and the ring of Barahir. Rivendell also became the place where the heirs of the Dunedain were brought up until Aragorn reclaimed Gondor and Arnor.

The valley of Imladris is now one of the lands owned by the High Kingdom of the Noldor after it's lord, Hand_of_Doom11, agreed to become one of the two founding members, along with Lindon.

Second Age
Rivendell was established by Elrond in the Second Age of Middle-earth in SA 1697. During the War of the Elves and Sauron, Eregion was laid waste and Elrond brought the survivors to Rivendell, soon Sauron laid siege to it but was eventually beaten back. Following the establishment of the Last Alliance of Elves and Men the hosts of Gil-galad and Elendil march to Imladris and laid camp in there to prepare their arms and then proceeded southeast to Dagorlad.

Third Age (Up until current)
When Angmar rose to power and conquered Arthedain, Elrond sent Glorfindel and a host of elves to meet with the armies of Earnil and Cirdan thus honoring the Alliance of Elves and Men. After the fall of Angmar the heirs of Isildur were fostered in Rivendell.

Source: https://lotr.fandom.com/wiki/Rivendell