Tenzing Norkay and Edmund Hillary were the first to climb the world’s highest peak, Mt. Everest, on May 29, 1953. Neither man claimed to summit before the other, so it is unclear who actually is the record holder.

While about 5,000 people have summited in the decades since, Hillary may still hold the “absolute height” record, since he was quite tall, at 6 feet, 6 inches. Given the mountain’s height of 29,031 feet 8 inches, when Hillary stood on the peak, the top of his head reached 29,038 feet 2 inches. While records are not kept on climber height, statistically, it’s unlikely anyone taller has ever stood on top of Everest. There is also no evidence that any summiter has ever sat on the shoulders of another summiter. While this maneuver, in theory, could best Hillary’s “absolute height” record, it’s improbable, given that summit hijinks and horseplay are discouraged.