Pokémon FireRed and LeafGreen/Navel Rock

'''Navel Rock is an uncharted island between Floe Island and Chrono Island. Its topographical location is a closely guarded secret, as it is said to be home to a duo of legendary Pokémon who watch over the seas and the skies: Ho-Oh and Lugia. Should this information fall into the hands of a power-coveting madman, it would spell disaster. Those deemed worthy to visit Navel Rock are presented with the Mystic Ticket, which will allow them access to this mysterious locale.'''

In order to access Navel Rock, you will need a Mystic Ticket, which is only available through Mystery Gift, or a Nintendo-sanctioned event. Unfortunately, this method is no longer viable due to the discontinuation of Mystic Ticket distribution. However, if you have a friend lucky enough to brandish the ticket, use the Mystery Gift to receive the ticket as a gift from them to access the island.

Option 1: Warp to Navel Rock
Should all else fail, there are underhanded ways of getting to Navel Rock- namely, Gameshark codes. If you own a Gameshark or have a Visual Boy Advance emulator with a patch, input the following codes depending on your game version:

Fire Red: Warp to Navel Rock Automatically 82031DBC 2402

Leaf Green: Warp to Navel Rock Automatically 6AADAC54 AQA4B6C7

Once you have the codes punched in, step through the nearest door or cave entrance you see. You'll be taken to the port for Navel Rock instead. Disable the warping code as to not start a repetitive loop appearing at the port. Instead, you'll be able to access the entrance to Navel Rock after walking out from the port.

Option 2: Buy a Ticket
The second option is a touch more convoluted, but it isn't as cheap as warping straight to Navel Rock. First, input the master code that matches your game version into your Gameshark:

Master Code: Fire Red 72BC6DFB E9CA5465 A47FB2DC 1AF3CA86

Master Code: Leaf Green 72BC6DFB E9CA5465 56671F3A 6F4F4D6B

Next, input the following code to prevent the game from crashing:

DMA Code 8D671FD9 6F6BEFF2 78DA95DF 44018CB4

Once you've added this code, you'll need to add another version-specific code. This code is designed to allow the programming for the items sold in any shop in the game to be switched out with an item of your choice, so long as the code remains active:

Shop Code: Fire Red 0E12F25C BC489609 141BB87C 83D7018F 7A063220 5D82DF58

Shop Code: Leaf Green EAEF00BE 85EA8374 141BB87C 83D7018F 194F7975 5E68B89E

Now, add this code to the list already punched into your Gameshark:

Mystic Ticket Replaces Shop Items 2782EFCA 4EED1397

Finally, there's one more code to allow the sailor at the Vermillion City port recognizes you have a Mystic Ticket:

Sailor Notices Event Tickets Code: 07CF2578 E43B4EBF

Adding all the codes listed here will make it possible to obtain a Mystic Ticket and legally go to Navel Rock via a Seagallop Ferry.

Once every code is entered into your Gameshark, head into the nearest shop and make a purchase. Instead of the normal stock being displayed on the list of items available for purchase, everything will be replaced with an option to buy a Mystic Ticket for free. Purchase one ticket and leave the store. One check on the Key Items screen will confirm you now have a Mystic Ticket. (Note: If you were to turn the codes off but the shops still offer the Mystic Ticket, save the game and turn it off to clear out the effects they had on the game programming. Turn the game on, and the shop items should return to normal, but you'll need to re-enter the master code, DMA code, and "Sailor Notices Event Ticket" Code.)

Presenting the Ticket
If you have a Mystic Ticket by means of Mystery Gift, or by means of the second cheating method listed above, go visit Vermillion City's port and speak with the sailor manning the pier. He'll notice you have a rare and special ticket in your possession and offer to have you ferried to Navel Rock. Make sure you have a hefty supply of Pokéballs, preferably Ultra and/or Timer Balls, or, if you have them, two Master Balls. Accept his generous offer to reach Navel Rock, home of the legendary Pokémon Ho-Oh, the phoenix bird that surveys the skies, and Lugia, the draconian bird that watches over the seas.

Navel Rock
You'll arrive at the port that leads out to Navel Rock, a large island composed of an enormous stone that both rests deep into the water below and reaches up far into the sky above. A small entrance is situated in the middle of the rock, leading into an expansive cave.

After you enter the cave portion of Navel Rock, it's simply of matter of moving forward to find the legendary Pokémon that dwell here. No wild Pokémon will pester you as you make your way onward, through the rock. The first floor ends at a ladder, which takes you down a straight and narrow pathway. It's rather lengthy, but linear, so all you need do keep walking. There are two small sections that deviate from this main path, but they simply lead to dead ends. They were rumored to contain the TMs Sacred Fire and Aeroblast, the signature moves of Ho-oh and Lugia, prior to the final stages of the game, but no such luck awaits you here- after all, making the moves of legendary Pokémon TMs would be too exploitable, allowing you to give these moves to many, many other Pokémon, thereby ruining game dynamics by stacking the odds unfairly in your favor. Instead, keep going down the center path, where you'll eventually reach a wider section of the floor that has two ladders leading opposite directions: up and down. The descending pathway will take you to a grotto where a Level 70 Lugia dwells, while the ascending pathway will bring you to the summit of Navel Rock, where a Level 70 Ho-Oh will land before you.

Facing Lugia
At the very bottom of Navel Rock, after passing through a mind-numbing sequence of redundant rooms on your way down, Lugia sits quietly before you in a small basin of water. Speaking to it will cause the room to rattle as it springs to life and screeches, ready to battle.

Lugia, like Mewtwo, is a staggering Level 70. You will need a Pokémon that can stand up to its furious power. Lugia is also both a Psychic and Flying-type, so any Pokémon that can use Rock, Ghost, Dark, Ice, or Electric-type moves will effectively tear away at its HP. Lugia knows the following moves: Recover, allowing it to heal periodically and draw out the battle unless you can use Disable on it; Hydro Pump, which will wipe out any purely Fire, Ground, or Rock-type Pokémon; Swift, a guaranteed hit so strong at this experience level, it can spell doom for a weaker Pokémon; Rain Dance, which will crank up the power of Hydro Pump for 5 turns, but allow you to exploit the effects of the move yourself. Lugia, like many other legendary Pokémon, also has the Ability Pressure. Be cautious of how much PP gets used up out of your moves.

If you're lucky enough to be packing spare Master Balls, it wouldn't be a bad idea to make use of one on Lugia. Otherwise, you'll have little choice but to resort to using Ultra Balls on it after you've lowered its HP to critical levels and placed a status ailment on the legendary. If you've advanced far enough into the game to buy Timer Balls from the specialty shop at Two Island or have any from trading, they'll be at their best if the battle persists upwards of 30 turns.

Soon enough, you'll catch Lugia and fill in another slot in your Pokédex! Raise it to Level 77, and you'll be able to teach it Aeroblast, its intense signature attack.

You've got one legendary Pokémon in your clutches, but there's another one waiting at the top of Navel Rock. This is the one and only time in the game you can find two legendary Pokémon in one location- why pass up that opportunity?

Facing Ho-Oh
Following a slightly less drawn out climb to the peak of Navel Rock, walk up the seemingly deserted summit to find a surprise: a splendidly majestic bird will cry out from high above and land down in front of you to do battle- Ho-Oh!

Ho-Oh is on par with Lugia, likewise clocking in at Level 70. It is a Fire/Flying Type, very weak to Rock-type moves and to less of an extent, Water and Electric-type attacks. It, too, has the Ability Pressure, and knows an identical moveset to Lugia, but with Fire-type counterpart moves in place of Lugia's Water-type moves. Instead of Hydro Pump, Ho-Oh has Fire Blast, and Sunny Day in place of Rain Dance. Lugia itself would be a great matchup against Ho-Oh with the moves it currently knows- just as long as you don't make Ho-Oh faint. Stick to a Pokémon with a type advantage that can take the brunt of Ho-Oh's attacks. Capturing it with a Master Ball makes for an easy victory, but the Ultra and Timer Balls can be worth a try once more. It won't be long before you have this legendary in the bag, and you'll have the superb Tower Duo all to yourself!

Like Lugia, Ho-Oh will learn its own signature move, Sacred Fire, at Level 77, and it's well worth the wait.

The Sacred Ash
Before you make tracks from Navel Rock after snagging Ho-Oh, there's a unique and phenomenal item hiding just under your feet. Activate your Itemfinder- you'll notice stars are shooting off from where you're standing, then get a message that the Itemfinder is shaking wildly! You're standing on top of a buried object, and now's your chance to dig it up! What you'll find is the outstandingly useful Sacred Ash- powdery cinders that were made from Ho-Oh's potent flames. This mother-of-all items will revive any and all fainted Pokémon on your team when used! Just think- this is your trump card against the Elite Four! But beware- it works only once, and when it's gone, it's gone. If you don't want to use it and have it disappear from your inventory, it's always a nice trinket for bragging rights- they're the spoils of an awesome Pokémon battle!

The Tower Duo
Ho-Oh and Lugia are fearsome contenders in any Pokémon battle. Lugia's Hydro Pump allows it to cover for its weakness against Rock-types, while Ho-oh has less potential weaknesses (Water and Electric) at the expense of one crippling Achilles heel against Rock attacks (4x damage). Neither can be harmed by Ground attacks, and they can heal themselves in battle with Recover. However, like many exceedingly strong legendary Pokémon, they are prohibited from use in the Pokémon Tower. Regardless, when both hit Level 100, they'll have monstrous stats well capable of dealing with the Elite Four in future rematches.

With your newly-acquired legendary Pokémon added to your crew, you can safely write off Navel Rock and depart. But... one other Event-exclusive Pokémon lurks in waiting- one with the strangest and most mysterious origin thus far. Rounding out the final entry in your Gen. III Pokédex, Deoxys awaits your arrival at Birth Island...