Catch Lugia & Ho-oh in Fire Red/Leaf Green!

Rough translation follows. Anything in brackets is a word or words I'm not certain about in context.

Mysterious Ticket (Distributed Letter?) Decision!!
In Pokémon Fire Red / Leaf Green, it is possible to meet Lugia and Ho-oh by going to Navel Rock with a very important tool!
Navel Rock is?...............
If you hold the Mysterious Ticket, you will finally be able to go to Navel Rock, in the center of Nanashima's Map. Wait in the opened island rock cave's deep depths to recieve...Lugia and Ho-oh! Wait in their respective places! Make the most of your skill, and capture them for sure!!