A ramp
A ramp on Dytallix B
A ramp was a sloped platform used to enable one to travel from one height to another.
Many ships were equipped with ramps. In 1986, two garbage men were startled by the sudden appearance of the HMS Bounty's ramp and a Human figure. (Star Trek IV: The Voyage Home)
Ramps were among the left technology on the abandoned mining planet Dytallix B as of 2364. (TNG: "Conspiracy")
Ramps were a component in Parrises squares. In 2367, Jean-Luc Riker fell off the ramp and broke his wrist. (TNG: "Future Imperfect")
In 2370, the Cardassian design of Deep Space 9 made it difficult to add ramps to assist Ensign Melora Pazlar in moving about the station in her wheelchair. (DS9: "Melora")