The Hunter's Lodge is an advanced building which allows you to forge new battle items using Titan Parts.
The Hunter's Lodge feature becomes available once your Stronghold has been upgraded to level 21. Once the Stronghold has been upgraded, you can start converting a building that is over level 5 and offers you the option to 'convert' to the Hunter's Lodge. Mines, Farms, Training Camps or Forges can be converted into the Lodge.
Converting a building to a Hunter's Lodge costs Iron. Once you have upgraded a building to the Hunter's Lodge, you can move it by converting any suitable building without a cost or loss of progress.