It's about one-and-two-fifths times as tall as The Challenger Deep (Marianas Trench).
In other words, 15 kilometers is 1.3759 times the height of The Challenger Deep (Marianas Trench), and the height of The Challenger Deep (Marianas Trench) is 0.7268 times that amount.(near Marianas Islands, a.k.a. Ladrones Islands, northwestern Pacific Ocean) (depth below sea level)
It's about one-and-two-fifths times as tall as Maxwell Montes.
In other words, the height of Maxwell Montes is 0.71 times 15 kilometers.(Ishtar Terra, Venus)
It's about one-and-two-thirds times as tall as a Mauna Loa.
In other words, 15 kilometers is 1.636 times the height of a Mauna Loa, and the height of a Mauna Loa is 0.6112 times that amount.(Hawaii) (Hawaiian island volcano) (total height from seafloor)
Mauna Loa, one of the five volcanoes which forms the island of Hawaii and the tallest mountain in total height in the world, rises to 9.2 kilometers above the seafloor. The peak of Loa is home to the approximately 6,000 sq. m (0.6 ha) Lake Waiau, one of the highest altitude lakes in the United States outside of Colorado.
It's about one-and-seven-tenths times as tall as Mount Everest.
In other words, 15 kilometers is 1.69 times the height of Mount Everest, and the height of Mount Everest is 0.592 times that amount.(a.k.a. Mount Chomolungma, a.k.a. सगरमाथा, a.k.a. Chajamlungma, a.k.a. ཇོ་མོ་གླང་མ, a.k.a. 珠穆朗玛峰, a.k.a. Zhūmùlǎngmǎ Fēng) (Sagarmatha Zone, Nepal and Tibet, China) (to summit, excluding snow depth)
It's about three-fifths as tall as Olympus Mons.
In other words, 15 kilometers is 0.56 times the height of Olympus Mons, and the height of Olympus Mons is 1.8 times that amount.(a.k.a. Mount Olympus) (Mars)
It's about two times as tall as Aconcagua.
In other words, 15 kilometers is 2.1546 times the height of Aconcagua, and the height of Aconcagua is 0.46412 times that amount.(a.k.a. Cerro Aconcagua) (Mendoza, Argentina)
It's about two times as long as The Las Vegas Strip.
In other words, 15 kilometers is 2.2 times the length of The Las Vegas Strip, and the length of The Las Vegas Strip is 0.45 times that amount.