The Ancient Ruins is an area in Zelda: Link's Awakening you explore after completing the Catfish's Maw.
Completing it - and the Armos Knight boss within - is required before you can access the Face Shrine.
If you're looking for more assistance, our Zelda: Link's Awakening walkthrough can help.
How to explore the Ancient Ruins
Before you continue, we recommend you get the Bow. This is purchased from the Mabe Village shop for a whopping 980 Rupees.
By now you should easily have enough saved up since there's little else in the game to spend money on - unless you really, really like the Trendy Game, of course. If not, we recommend playing some Chamber Dungeons to help top up your finances.
After you've completed the Catfish's Maw, you'll want to head north of Animal Village, specifically north of the staircase you used to get there, to a thin path running along the water.
As you go, the owl will appear and advise you visit the Ancient Ruins to the south. Head right, picking up the rocks to move them out of the way, then at the end is the entrance to the area.
As you explore the ruins, statues will come to life. There are several ways to deal with them - bombs will kill them outright, a sword swipe will buff them back, otherwise the hookshot will stun them.
It's a linear route, and if you are seemingly at a dead end, work you way round until there's a statue. Chances are it'll come to life, and move so you get through.
Enter the building at the far end, then go north to face the Armos Knight.
Our Zelda: Link's Awakening walkthrough and guide can help you with the critical path, including the Eagle's Tower and Turtle Rock dungeons. There's plenty to be done on the side, too - including Zelda Link's Awakening Heart Pieces, Zelda Secret Seashells and the Zelda Link's Awakening trading sequence. Finally, there's also the new Zelda Chamber Dungeons feature to unlock and complete.
Armos Knight boss strategy
Despite the simple attacks, the Armos Knight is a tricky foe - it'll jump and when it lands, will knock you over, and attempt to corner you, easily done with its size.
To damage it, the easiest way is to use the Bow. Leap using Roc's Feather just before it lands, then use an arrow to damage it. You can also use a spin attack (hold the B button and release when the sword is charged) but this takes a little longer and can leave you open after you land yourself.
After enough strikes - he'll glow red when you land a successful attack - he'll lose his shield, then some of his armour, then be defeated.
Once done, grab the Face Key and investigate the mural on the wall in the next room.
That's all to do here - so leave, escape the Ancient Ruins the way you came, and head north, picking up rocks to move through the small maze.
Swim out to the south to a thin island with two statues end to end. Run into the left statue until it comes to life, lay a bomb and use the staircase underneath.
Use the hookshot to get across the gap, then head up and use the key in the keyhole on the right, opening the way to the Face Shrine.