Location from pokemon-adventures-frlg by
The first island Red and Blue reach -- home to Celio's Pokemon Network Center and the starting point of Ultima's training.
One Island is where the arc begins in earnest. Red and Blue arrive by ferry and meet Celio, who needs their help with the Network Machine. Ultima finds them here and drags them to Two Island for training. Bill stays behind to work on the machine and watch over the unconscious Green. Mt. Ember looms over the island -- a dormant volcano whose heat is the source of the island's geothermal activity. The Rocket Warehouse's entrance was originally hidden near here before Team Rocket moved operations to Five Island.
A small volcanic island dominated by Mt. Ember. The town at its base is modest -- a Pokemon Center, the Network Center, and a harbor. The air smells of salt and sulfur. Kindle Road winds along the coast toward the volcanic peak.
Also known as: One Island, Knot Island