Ultramarine Stronghold

Ultramarine Stronghold - is an area in B3313.

Description
As might guess from the name, this is a solid stronghold, surrounded by water and mines and guarded by goombas, bob-ombs, Chak-yas and Motos. Beneath the fortress is a network of water tunnels, also filled with mines. There are grates in the tunnels, so need to turn on the Vanish Cap Switch before passing this level.

Origins
It appears to be an original creation.

The music is a water theme from Super Mario Bros played in the Super Mario 64 sound font.

Stars

 * Collect 8 red coins.
 * Collect the star at the top of the stronghold.

Leading here

 * 4th Floor: Enter the upper left door, then jump into the painting.