Olivine City is Johto's city port. Jasmine's gym (6th) is here. Johto's lighthouse is here, which in addition, houses an Ampharos, named Amphy by Jasmine. that has to be cured with the Secret Potion retrieved from Cianwood City. Connected by Routes 38 and 39 that lead to Ecruteak City from the northwest, and connected by Route 40 and 41 that ultimately leads to Cianwood City from the southwest. After Johto's Elite Four are defeated, there is a port here that allows you to travel and start off in Kanto. Once you defeat Sabrina in Kanto, she will be at the port on Sundays. You will be able to add Sabrina to your phonebook.