Trivia: More than 500 what are hidden in the canyon?
Reptile species
Caves
Houses
Waterfalls
The correct answer is Caves
So why is this answer correct? : Only one cave in the entirety of the Grand Canyon is open to visitors: the Cave of the Domes, which is located on Horseshoe Mesa. To date, 335 caves have been recorded in the canyon, and geologists estimate that about 700 more are hidden in the canyon walls. Fossils, artifacts, and unique mineral formations can be found in the caves.