The Valley of Everlasting was a location on the planet Vulcan. It was known to had been an old eroded and beaten down location with the lava replenishing it and making the Valley anew.
In 2377, after the death of her husband Hasmek, Teska created a holographic representation of the Valley of Everlasting where she spoke to his murderer the guilty Jekrit. (TNG novel: The Genesis Wave, Book 3)