Olivine City is a coastal city which contains the Glitter Lighthouse as well as a dock which takes you to Kanto on the SS Aqua. In this city, you can also obtain seals for your PokéBalls

Cameron's Photos
On Mondays & Tuesdays, Cameron the Cameraman will appear by the Pokémon Centre and will take photos of you and your Pokémon team.

Special Photos
Everyday, between 12:00 and 13:00, if you have her phone number, Jasmine will appear and will allow for a photograph to be taken with you and your lead Pokémon.
At the dock, on Mondays & Fridays, if you have her number, Sabrina will appear and will allow for a photograph to be taken with you and your lead Pokémon.

Gym
The Olivine City Gym is the sixth gym of the Johto region. This gym has no extra trainers and is only accessible after you have healed Amphy in the Glitter Lighthouse. Go up the path until you reach the Gym Leader; Jasmine. Earning the Mineral Badge allows you to use no extra move outside of battle. Later in the game, you can trade with Jasmine to get her Steelix

Special Moves used in :
Surf
Rock Climb