Where do you go after beating the gym leader Sabrina in Pokemon Blue?

After defeating Sabrina, the Gym Leader of Saffron City in Pokemon Blue, you can head to the next town, Fuchsia City.

You can reach Fuchsia City by heading south from Saffron City.

Here's a quick rundown of what you can do after beating Sabrina:

* Fuchsia City:

* Challenge the Gym Leader, Koga, who specializes in Poison-type Pokemon.

* Catch the rare Pokemon, Snorlax, in the nearby Route 16.

* Visit the Pokemon Safari, an area where you can catch unique Pokemon.

* Get the TM for Toxic at the Pokemon Center.

* Explore other areas:

* Route 15: Find the TM for Thunderbolt.

* Route 16: Catch Snorlax, encounter various other Pokemon, and find the TM for Thunderwave.

* Route 12: Explore the area and find the TM for Thunder.

Remember, there are many other things you can do after beating Sabrina, but this gives you a good starting point. Keep exploring the world of Pokemon Blue!