How do you get to seaside cave in Pokemon black 2?

To reach Seaside Cave in Pokémon Black 2, head to the lower section of Route 21, which is located south of Virbank City. Look for the entrance on the southern edge of the route, where you'll find a cave entrance near the water. Inside, you can explore the cave and encounter various Pokémon, as well as trainers. Make sure to bring Surf to navigate the nearby water areas if needed.