Beat misty then go to cerulean cape
Cerulean cape is the area north of Cerulean City. It is just north of the bridge that connects the cape to Cerulean City. The cape is any land that is above the Bridge that connects the cape to Cerulean City.
After defeating Blue, go to Cerulean Cape between 4:00 PM and 6:00PM unless Suicune is there.
To get to the cerulean cape you go north on the bridge and head east. You'll have to battle 5-7 trainers on the way. When you get to the end you'll met misty and some other guy, misty will then go back to the gym. After the gym if you have chased suicune enough it will be where you met misty. =)
The cape you might be talking about is Cerulean Cape, which is north of Cerulean City. Follow the orange and white bridge north from Cerulean to get to the Cerulean cape. The shady guy will first be on that bridge, and then north to the actual cape itself.
at cerulean cape which after you encounter suicune for the 3rd time is where it will be and after you catch it or beat it you will find her
After you get to Kanto and talked to Eusine, go to the cape outside of Cerulean.
You find Suicune sitting on the Cerulean Cape (where Misty was at before she went back to her Gym) after you have found it in Cianwood City, near the Mt. Mortar entrance, Vermilion City and Route 14, it must be chased off each time until you get to the Cerulean Cape. Suicune will only be on Cerulean Cape after you have defeated Misty in a Gym Battle.
On Cerulean Cape
after u follow suicune all over johto, beat the pokemon league. then follow it around kanto. you will also run into eusine several times. after he realizes that suicune likes hills and water go to cerulean cape in kanto after u beat the cerulean gym. suicune will be waiting for u.
Cerulean Cape after finding him on other routes.
you catch it when you have 'ALL' 8 badges of Kanto and Johto. (equals up to 16 badges altogether.) and you have kept chasing it until you battle him/her at cerulean cape... and then, you can catch him/her...! i hope I've helped :)
Beat misty then go to cerulean cape
At the end of route 25, north of Cerulean City.
you need to see it in these places: burned tower cianwood city north route 42 ss aqua port vermillion route 15 cerulean cape (battle)
If you go deep enough into it, you can catch mewtwo
Olivine town, Outside Mt motar, Vermillion city then Cerulean cape