In olivine city.
Cinawood city, which is in the next town after the one with the lighthouse.
Secret Potion
in order to do that you have to help the lady in the lighthouse
you go to the city before the safarie zone.
The lighthouse is in Olivine city at the lower right corner of the city.
The Lighthouse is in Olivine City.
go to the town near the ocean. i forget the name. there go to the left and up some stairs
Go up the stairs and all ladders u can then go through the window on the right
ampharos
To get the medicine for the Olivine Lighthouse's Ampharos you must have a Pokemon that knows surf. Surf to Cianwood, get the medicine from the medicine shop, surf back to Olivine, and give the medicine to Ampharos.
go to olivine city and so go into the lighthouse
The lighthouse is in Olivine City, where the gym leader Jasmine is.