Obmuer Temple’s exterior door requires four Triangular Slates. Search the flooded ruins outside the temple: the fork beyond the round tower, the broken wall beside the ramp, the shallow-water fallen pillars and the platform northeast of the ramp. These are entrance pieces, not the Trident Keys used inside.
Start at Aganmi’s Camp
You need Endu and two Wind Dashes to reach the intended western route. If the broken bridge is your current obstacle, use the Wind Gem route before searching for slates. Begin the exterior search from Aganmi’s Camp Crystal Monument and save there.
The flooded approach contains Coelacudas and a group of Red Nibblers near the broken wall. Draw enemies onto manageable ground before investigating narrow platforms. The collection order here follows ShowGamer’s walkthrough; numbered slates are a checklist for this route, not distinct in-game compass labels.
First slate: the fork beyond the round tower
After the Red Nibbler section, pass through the round tower to the fork. Take the left branch and inspect the rock around the corner. The first slate is there, with skeletal enemies nearby.
You can retreat toward the tower for more space instead of fighting beside the pickup. This is also a useful return landmark: the second leg begins by coming back to the same round tower and taking the other branch.
Second slate: broken wall beside the ramp
Take the right branch from the tower and continue toward the stone ramp with water underneath it. Watch for the ceiling-mounted Barnacle as well as enemies below the ramp. Clear those threats before concentrating on the jump.
Climb the ramp, turn right toward the damaged wall and Wind Dash across to the second slate. Dash back onto the route after collecting it. Farther up this area is the Trident weapon near a statue, with the temple entrance down the nearby ramp. Finding that weapon does not mean you have finished the slate search.
Third slate: shallow water behind a fallen pillar
Return toward the shallow water near Aganmi’s Camp. Locate a fallen stone pillar and dash across to the water beyond it. ShowGamer describes several Glaucusions here, so secure the landing before inspecting the surroundings.
Look southwest for another fallen pillar. The sparkling pickup behind it is the third slate. Climb onto the pillar afterward and return toward the entrance ramp. This low route is easy to overlook if you only search the upper masonry around the Trident.
Fourth slate: northeast platform from the ramp
From the ramp, look northeast toward the separated platform. Landing triggers skeletons on a small fighting surface. The published route advises returning to safety with a double dash, clearing them at range, and then crossing again.
The final slate is on the far side of that platform. Let your movement charges recover before the return trip. Use the camp monument to preserve the completed collection, then bring all four pieces to the entrance sockets.
What opens next
Once the exterior entrance is open, follow the Obmuer Temple interior route. Its Sapphire and Emerald Trident Keys solve a different set of locks. A missing slate is therefore an exterior search problem; it does not require leveling the Trident or buying an optional key.
Sources and scope
The detailed route follows ShowGamer’s four-slate walkthrough. The island walkthrough corroborates the four-piece exterior requirement but describes landmarks differently. This guide uses one consistent round-tower/ramp route rather than mixing incompatible directions. Reviewed November 5, 2026.