Instructions
Follow Route 9 east from Cerulean City. Cerulean City is located in the north part of the Kanto region and is accessible from all directions.
Defeat the six trainers you encounter along the route. Most of the trainers on Route 9 use ground and water type Pokemon. Attacks from grass type Pokemon will be significantly more effective against these enemies.
Continue following Route 9 east until you reach a field with a row of trees. Walk straight north until you reach a body of water. Use your "surf" ability to enter the water. If you do not have a Pokemon with the "surf" ability in your party, you will need to visit a Pokemon center and withdraw one from storage. To reach the nearest Pokemon center, travel south on Route 10.
Follow the river south until you reach a large building (the power plant). Exit the water and enter the power plant.