Borobudur is a stepped pyramid on a quadrangular plan. It had been built on and over a natural hill so, like a stupa, it has no interior space. There is no roof and all of its galleries and terraces are open to the sky.  The lowest level has a square floor plan, each side 370 feet long.  Melody and Nine rode on Jet surfboard to fly over the steps. Borobudur is very hot place but fresh air on the Jet surfboard is comfortable to them.