My trap corridor from my last Dwarf Fortress game

Trap corridor

D = Draw bridge
C = Cage trap
W = Weapon trap
S = Stone fall trap
B = Normal retracting bridge

  
  <-  Entrance
|DDD|  <- draw bridge that acts like a portcullis
|CCC|
|WWW|
|SSS|
|BBB|
|BBB|  <- First bridge
|BBB|
|CCC|
|WWW|
|WWW|  <- Death island
|WWW|
|SSS|
|BBB|
|BBB|
|BBB|
|BBB|  <- Oh fuck bridge (15 or so z level drop underneath)
|BBB|
|BBB|
|BBB|
|CCC|  <- Cage traps incase I am too slow with levers
|SSS|
|SSS|  <- Well shit they got this far maybe these crappy stonefall traps will work?
|SSS|
|SSS|
|   |
|   |
|   |
|   |
    |
    |
|---|
   <-   catapult for killing goblins that stranded on the island


Most common usage is to retract the two bridges and close portcullis in the event of goblin incursion. Any goblins that survive the traps can then be disposed of at the lesure of the catapult operators. Note that this configuration does not do much to protect against flying enemies.