How do you get to snowpoint temple in Pokemon Platinum?

Answer 1

Snowpoint temple is in the back of snowpoint city. In order to enter though you need to have beaten the Pokemon league and completed the sinnoh pokedex.

by Electchu: how in the world do you get to complete the sinnoh pokedex with out regigigas?

Answer 2

all you have to do is get a national poke'dex by copleating your sinnoh one

then go visit the temple and the guard will not let u in but the gym leader will come and let u in