Drawbridge
A drawbridge was a feature of a castle or fortress that allowed one to cross a moat or other impediment and enter the building.

Doctor Chaotica's Fortress of Doom was equipped with a drawbridge. In a 2375 playing of The Adventures of Captain Proton holoprogram, it was lowered twice; once for Lonzak and his prisoners, and once to admit Queen Arachnia. ()

External link

de: Zugbrücke
The Adventures of Captain Proton
Architecture