The stronghold on this seed is far away from the spawn point, but it’s still easy to get to. Not to mention, it’s worth the journey because you’ll find an abandoned mineshaft and the stronghold together. To begin your journey, all you need to do is craft a boat.
Minecraft PC 1.10.X Seed: -1075018877
When you spawn, you’ll be on a small patch of plains, facing an extreme hills biome. You can go get a tree from the patches east of you to craft a boat. Once you’ve done that, return to your spawn point and get in the ocean. You want to head south along the edge of the extreme hills.
Just keep paddling through the deep ocean, following the edge of the extreme hills south and west. You can observe the scenic biome next to you as you go.
Finally, if you watch under the water, you’ll see the end portal room under the ocean at around the coordinates of -863 / 62 / 1115. This portal room is completely underwater, but there is no water inside the room.
The rest of the stronghold is a bit tricky to get to because there’s no cave leading to it. You have to mine down to it instead. Go to the stone area by the portal room and you’ll see a little indention facing north. (As pictured)
If you go in there and mine straight down from one of the blocks near the wall, you’ll eventually fall into the stronghold. I chose the -829 / 68 / 1135 block, and it dropped me into the room pictured below.
You can explore around the endless halls and see if you can find any of the chests usually in strongholds. As you wander around, be careful to not get lost. There are a lot of twists, turns, and dead ends. You may also stumble across the abandoned mineshaft that intersects with the stronghold.
So not only can you look for the regular chests distributed around the stronghold, you can also keep your eyes out for minecart chests in the mineshaft. This stronghold/mineshaft combination is surely stuffed full of great finds. Enjoy!