The Pokeathlon Dome did not exist prior to Heartgold/Soulsilver, so it wasn't in Crystal.
Go to the national park and from there you should be able to the pokeathlon dome in poke mon heart gold.
On Pokemon Soul Silver and Pokemon Heart Gold, you have to defeat the Goldenrod City Gym Leader, Whitney, and then she tells you that the construction for the Pokeathlon Dome is complete.
you jump 1000 times
Travel north of Goldenrod City between routes 35 and 36. The Pokeathlon is connected to the National Park.
The Pokeathlon Dome did not exist prior to Heartgold/Soulsilver, so it wasn't in Crystal.
You can buy a sunstone from the pokeathlon shop inside of the pokeathlon dome
Go to the national park and from there you should be able to the pokeathlon dome in poke mon heart gold.
at the pokeathlon dome on Thursday
On Pokemon Soul Silver and Pokemon Heart Gold, you have to defeat the Goldenrod City Gym Leader, Whitney, and then she tells you that the construction for the Pokeathlon Dome is complete.
as a prize in the pokeathlon dome on certain days
At the pokeathlon dome as a prize on Wednesday.
you jump 1000 times
Travel north of Goldenrod City between routes 35 and 36. The Pokeathlon is connected to the National Park.
you can earn it in the pokeathlon dome on specific days
no get them at the pokeathlon dome
You buy it with points at the Pokeathlon Dome.