There is no shortage of hidden areas in the Pokémon games. Typically these hidden areas are little side trails that lead to a common item like a Pokéball or potion; however, these hidden areas occasionally are not only a little harder to find, but give the player something special for their effort. In the later games this “something special” was usually a legendary Pokémon, or an item that would change the game in new (and un-thought of) ways.
Many of the hidden areas on this list are insanely difficult to reach without help from our friend Wiki – in fact some have probability factors associated with them so low it is unlikely many players found them on accident despite multiple playthroughs.
10 Sealed Chamber – Ruby, Sapphire, And Emerald
This is a hidden area in Ruby, Sapphire, and Emerald that is very out of the way. The player needs to have Relicanth, Wailord, and a Pokémon that has learned Dig. The player needs to go to Route 134 and find the correct dive spot.
This leads to the Sealed Chamber, where the player must solve a braille-based puzzle and use the Dig move. In the second chamber the player must have Wailord and Relicanth in the correct position within the party – this causes an earthquake which unlocks new areas. This earthquake also makes Regis available to be caught.
9 Mirage Island – Ruby, Sapphire, And Emerald
This is easily the hardest hidden area to find in the series. This island will (extremely infrequently) appear along Route 130. Every day the game will produce a random number between 0 and 65535. If the first two bytes of a Pokémon’s personality value (in the party) matches this number, Mirage Island will appear.
With a full party of six this gives the player a 1/10923 chance of the island appearing each day. The island has a small grassy area where the player can catch a Wynaut. The true treasure of the island is the Liechi Berry the player can pick. This is the only Liechi Berry in the game.
8 Birth Island – Fire Red, Leaf Green, And Emerald
This small island is accessible in different ways depending on whether someone is playing Fire Red and Leaf Green, or Emerald. In Fire Red and Leaf Green the player reaches the island via the Seagallop docks; in Emerald the player gets to Birth Island via the S.S. Tidal.
Birth Island is a small triangular island with a small triangular stone. The player must solve a simple puzzle involving this small stone to make Deoxys appear and attack. Each of the three versions has a different version of the legendary Deoxys to catch.
7 Sinjoh Ruins – Heart Gold And Soul Silver
This is another hidden area that many players might possibly never visit themselves. The player can get to Sinjoh Ruins through the Ruins of Alph. The player must also have Arceus in their party to activate the necessary dialogue.
The problem is that Arceus is not a Pokémon that is normally attainable in Heart Gold and Soul Silver – it is only available during special events. If a player has managed to acquire an Arceus they will be given a choice of getting a Dialga, Palkia, or Giratina. These three Pokémon are among the most powerful in the series.
6 Nameless Cavern – Omega Red And Alpha Sapphire
The Nameless Cavern is a hidden area along Route 126 in Omega Red and Alpha Sapphire. Being able to find this area requires a few conditions be met first. The player must have three Pokémon with maximum friendship values in their party.
Also, the players must be flying (soaring) on Latias or Latios. Inside the cavern, players will find a floating ring with which they can interact. Doing so will make Uxie, Azelf, or Mespirit appear – the player can then attempt to catch it. Which Pokémon appears is dependent on the time of day.
5 Trial Chamber – Black And White
This is the smallest hidden area on this list by far, but the reward is well worth it. The Trial Chamber is a (sort of) hidden area along Victory Road in Pokémon Black and White. The entrance is covered by a large immovable stone.
To move this stone the player must have first caught the legendary Pokémon named Cobalion - Cobalion can be encountered in Mistralton Cave. With the stone removed the player is free to enter the Trial Chamber and face the legendary Terrakion – a bull shaped Pokémon of incredible power. Terrakion is at level 42 when encountered.
4 Lake Of Outrage – Sword And Shield
Pokémon Sword & Shield, the newest offering in the Pokémon franchise, also has quite a few hidden areas for players to find. One of these areas is the land on the other side of the Lake of Outrage – located near the Giant’s Cap.
Getting across the lake requires the use of the Rotom Bike, which allows travel over the water. There are three areas where wild Pokémon can be caught, a Pokémon den, and three useful items; the Assault Vest, Focus Sash, and TM65 (Shadow Claw). In addition, players have a chance of encountering some rare Pokémon in the den.
3 Hidden Cave In The Whirl Islands – Silver, Gold, And Crystal
The Whirl Islands are located in the sea south of Olivine City. To access the hidden underground area the player will need Pokémon in the party that have learned the Surf and Whirlpool abilities – the two moves don’t need to be known by the same Pokémon.
After heading south from Olivine City for a bit, the player should see a whirlpool on the left side of the screen. Using Whirlpool will clear the path to the beach on a small island with a cave entrance. Inside the cave the player can catch the legendary Lugia.
2 Turnback Cave – Diamond, Pearl, And Platinum
Turnback Cave is located south of Veilstone City along Route 214. The player will need a Pokémon with the Rock Climb ability to access the cave being guarded by Cynthia; after beating her the player can enter the cave.
The player goes through a series of random rooms hoping to find three rooms with pillars. Upon finding the third pillar the player has a chance of catching the legendary Giratina. The cave also has some other useful loot, like some Stardust, a Nugget, a Rare Bone, and Reaper Cloth.
1 Unknown Dungeon – X And Y
The Unknown Dungeon in Pokémon X and Y doesn’t have much in it, except maybe the most powerful Pokémon in the series. Getting to this cave requires that a few conditions be met. The first and most difficult is that the player must be in the Hall of Fame – meaning beating the Elite Four and the Pokémon Master for that region.
The dungeon is located in southeastern Kalos, and the Surf move is needed to reach the entrance. Waiting inside the Unknown Dungeon is Mewtwo. The player can not only catch Mewtwo here, but also find some Mewtwonite. On one of the stalagmites the player can also find an Oval Stone.
NEXT: Pokémon Sword & Shield: 10 Ways To Increase Friendship With Your Pokemon
