The maze is actually pretty easy, but takes a while. Make sure to have good fire types and ground types. She's a pretty easy leader once you get to her.
sownpiont city
ice/snow types
She has medichan,snover abisnow,and sneasle
mount cornet
Have a strong fire type pokemon.
Candice is the 7th/snowpoint city gym leader
get action replay!
gym leader:candice pokemon:sneasel medicham snover and abomasnow (the final evolved form of snover)
The seventh gym is located in Snowpoint City at the very top of the map. You need to get through Mount Coronet and 2 snow routes to get there.
In Diamond, Pearl and Platinum 7th gym is in Snowpoint Town.
The seventh gym leader in Pokemon Diamond is located in Snowpoint City. Her specialty is Ice type Pokemon, so make sure and have a powerful Fire type. Good luck!
the best way to beat the 7th gym leader is with a fire type Pokemon