This is not an official term.
A stairway of 777 stone steps led from the surface of Voya Nui to the Chamber of Life.
There were two different pathways to the Kanohi Ignika to ensure the Toa got their own nightmare rather than walking in on the Piraka's.1
Most challenges along the 777 stairs were on the stairs themselves, though Umbra and the protodax were in a chamber.2
Challenges along the 777 stairs were either on the stairs themselves or on landings along the stairs.3
The 777 stairs were a straight path.4
The Ignika's guardians mostly worked separately to stop intruders, but Umbra and the Protodax were very close geographically.5
A lone being wouldn't trigger the tube trap the Piraka encountered, as the purpose of that trap was to test trust and teamwork.6