Reach the Hammer from the higher pipes
To reach the Hammer above the sewer bars, use the water-control wheel behind the hub stairs, swim to the old pipes, and follow the higher pipe route to the tool. Once you collect it, you can break rusty metal barriers and open the route toward the lower forge.
Prepare Rope and stamina before descending
The sewer entrance uses the rope descent behind the stairs in the hub. If you need Rope, craft it in the Crafting menu from 2 Vines and 1 Stick. Keep the descent available for your return trip.
Start the swim with full stamina and aim for the old pipes. Leave inventory space for the Hammer before setting out. Collecting the tool is your priority; save optional gathering until you have it.
Follow the water wheel and pipe route
- Turn the early sewer water-control wheel behind the hub stairs to change the water level for the approach to the old pipes.
- Descend the rope behind the hub stairs to enter the sewers and begin the approach to the Hammer.
- Swim across toward the old pipes with full stamina, passing the eel on the way to the climb.
- Climb onto the rusty pipe route to gain height above the water and approach the upper rusty-bar area.
Follow the higher pipes toward the Hammer, crouching where needed to continue along the route.Playing this video connects to YouTube.
- Pick up the Hammer above the rusty bars to obtain the barrier-breaking tool and unlock its replacement recipe.
- Strike a breakable rusty metal barrier with the Hammer to clear a passage through it.
Break the rusty gate toward the lower forge
Use the Hammer on breakable rusty bars, fences and grates. A useful next target is the rusty gate down the stairs to the right of the big door in the hub. Breaking it opens the route toward the lower forge and its key puzzles.
Further into the sewers, the Hammer also breaks a gate with a lime plant behind it. That gate lies along the approach to the final wheel needed to drain the section near the locked-door camp. Keep the Hammer with you when returning to explore those sewer passages.
Open the full dungeon walkthrough for the forge and key puzzles after collecting the Hammer.
Check the pipe approach and barrier type
If you cannot get onto the pipes, return to the early water-control wheel and change the water level again. Use the reachable pipe as your landmark for the approach. Once you are on the higher route, try crouching through tight sections toward the Hammer.
Equip the ordinary Hammer when breaking rusty fences. The War Hammer counts as a sword for obstacles and does not substitute for this tool. Solid prison-cell doors still require their actual locks.
Keep the Hammer or craft a replacement
Picking up your first Hammer unlocks its Workbench recipe. If you need a replacement later, craft it at the Workbench. Patch 1.0.51.0 reduced its Iron Rod requirement, so follow the materials displayed in your Workbench.
The Hammer is kept on death. Check your inventory after respawning before repeating the sewer pipe route. If you left it in storage, retrieve it before heading back to the rusty gates.