A peculiar cave located on the Eastern Glens. It's full of fossils, but it's hard to get into.

Encyclopaedia description

The Trilobite Cave is an optional dungeon in the MARDEK series. It is first available to visit in MARDEK Chapter 2: A New Hero and requires 4 trilobite keys that are hidden in the chapter in order to get to the end of the cave and reach Cambria, a village of trilobites. The locations of the keys are as follows:

  • Trilobite Key I can be found in the Tainted Grotto. On the floor where you fought the World's Saviours, there's a little pool of slime just south of where you battled them. If you check the pool, you'll find the key in there (look on your map; you'll see a treasure chest, which is invisible in the field screen).
  • Trilobite Key II is dropped randomly by a zombie in Canonia during Moric's invasion. Which one drops it is randomised (actually, each one has about a 10% chance of dropping it until you acquire it), so just keep defeating them until you get it. If you kill them all but still don't have it, just exit the area and come back; they'll all respawn.
  • Trilobite Key IV is given to you by Gope in the Goznor inn after defeating Muriance if you spared his life in the Gem Mine. If you didn't, you must start a new game in order to access the Arena content in MARDEK Chapter 2: A New Hero.

All keys can be purchased in Aeropolis in MARDEK Chapter 3: Keystones.

Monster formations

Random (all areas except entrance):

Treasures found


  • Chamber directly left of south entrance
    • 376 Gold
  • Southwest path from lakeshore
  • Lakeshore, west side
    • 137 Gold
  • Northeast corner of map
  • North branch of land jutting out into lake from eastern side of map
  • South branch of land jutting out into lake from eastern side of map
  • Northeast path from intersection near south entrance


  • J-shaped branch of land in southwest part of map
  • Chest overlooking lake in southeast part of map
  • From central exit, to south to the bottom of the map, east, north, west, and north to a chamber
  • From previous chest, go south, east, and north to a dead end at the northeast corner of the map
  • From previous chest, go south and then west to a dead end overlooking the centre exit
    • 476 Gold
  • From previous chest, go east, north, west, and south to a dead end overlooking the central path
  • Northwest corner of map, near northwest exit


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