Kendha-Ya was the name of an out-region on the planet Vulcan, also known as the Dead Ocean.
History and specifics[]
One part of it looked like a nigh-inhospitable wasteland, barren with steaming crater holes. Sand worms lived in this region. The Shin-Ka-Ti plant was known to grow only in this region, and nectar from that flower provided the only known cure for the Red Plague.
In the 2070s, the Red Plague which killed more than one million Vulcans erupted from here.
In 2279, Captain Spock visited the Kendha-Ya region to retrieve a Shin-Ka-Ti plant. He estimated his probability of dying there at 0.57808. While removing one of the plants, he was attacked by a sand worm, which he was forced to kill using a hand phaser. (TOS comic: "Terminally Yours")