Zeppelins were huge airships invented by humans in the 20th century. They were used as transport, as well as for military uses.
The Doctor and Susan observed a Zeppelin air raid during World War I. (DW: Planet of Giants)
In Pete's World, zeppelins covered the skies of London and were owned by the richest businessmen. (DW: Rise of the Cybermen)
A Cybus Industries Zeppelin was where Mickey Smith and Jake Simmonds defeated the Cybermen. This Zeppelin was later used as a means of escape from an exploding Cyber-factory. (DW: The Age of Steel) One account says that the Preachers used an armed Zeppelin to free Paris from Cyberman control. the Zeppelin used its weaponary to destroy Cybermen on the streets whilst retrieving civilians and scientists. The Zeppelin finally transmitted the code which disabled the the Cybermen emotional inhibitor and destroyed the Cyber-factory. (VG: Save Paris) Though another account suggests Zeppelins weren't used in the liberation of Paris. (VG: Cyber Assault)
In the episode "The Empty Child" Rose was hanging from a Zeppelin when she was rescued by Jack.