Kendha-Ya was the name of an out-region on the planet Vulcan, also known as the Dead Ocean. One part of it looked like a nigh-inhospitable wasteland, barren with steaming crater holes. The sand worm 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.
Captain Spock visited the Kendha-Ya region in 2279 to retrieve a Shin-Ka-Ti plant. He estimated his probability of dying there at .57808. While removing one of the plants, he was attacked by a sand worm, which he had to kill using a hand phaser. (TOS comic: "Terminally Yours")