How do you get to marvelous bridge Pokemon Black?

You can't get to Marvelous Bridge in Pokemon Black. It's a location from Pokemon White and is not accessible in Black.

To access Marvelous Bridge in Pokemon White, you need to:

1. Complete the main story: You need to have defeated the Elite Four and become the Pokemon Champion.

2. Travel to Undella Bay: Head to Undella Bay and speak to the person standing near the bridge. They will tell you about the Marvelous Bridge.

3. Obtain the "White Forest Key": To enter the bridge, you need the White Forest Key. You can obtain it by completing the "Special Event" in White Forest. This event involves finding 100 hidden items in the White Forest.

Note: The Marvelous Bridge is a unique location in Pokemon White and is not accessible in Pokemon Black.