Mario Circuit is a course appearing in Mario Kart 9th. It is the first course of the Flower Cup. The castle itself resembles the one of the Super Mario 64 version.
You start before the bridge, you drive over the bridge through the gate of the castle and go inside. There is a wall in the middle of the room. You can go left or right and on both sides are item boxes. As you continue you leave the castle, drive over the bridge and have to make a right turn. There is a sharp u-turn, but you can also take the shortcut with a drift boost jump or a mushroom. You drive underneath the road and go further where some item boxes are scattered on the road. You drive under the road again and make a right turn and have to watch out for the pipes on the sides. Then you came at the jump in which you paraglide through the stained glass of the castle, land on a platform in the castle and do another paraglide jump. As you land item boxes await you. You make another right turn and have to watch out for the big Piranha Plant. You go underwater and drive under the bridge where there are some item boxes. You go out of the water again make another right turn, pass some Piranha Plants and go to the finish.
Another route you can go at the paraglide is go down into the water and enter the sewer of the castle. There are several twists and turns so it is practically as long as the upper route. Although there are more chances to drift when underground in the water.
The castle, like said above, looks like the castle of Super Mario 64. Inside of the castle are several paitings on the side from Super Mario 64. The background is the standard background for the Mario Circuit stages, thus mainly a few hills and trees in the background and smiling clouds. Inside and on the bridges of the castle are Toads. There are little flowers etc. etc.