Ladder

A ladder was a tool used to climb to higher areas. Rope-ladders were often attached to helicopters and other vehicles capable of flight. (TV: The Invasion, World Enough and Time)

The Third Doctor and Tom Streeter used a ladder in Africa to enter the depths of a Volcano. (COMIC: Trial of Fire)

A board game entitled Snakes and ladders used illustrations of ladders to signify moving up in the board. (PROSE: Time and Relative, et. al)

In battle, ladders were used by humans to reach and penetrate fortifications. As part of the Dalek Project, time travelling bronze Daleks engaged humans using such measures. (COMIC: The Dalek Project)