From the Super Mario Wiki
Wario Dunes is a sand court in Mario Tennis Open for the 3DS. It is set in a desert where cacti and an Egyptian pyramid can be seen in the background. There is another pyramid at the front of the court, similar to the one that appears in Wario Land 4. It has ruined sand bricks surrounding the court and it is heavily based on Super Mario desert levels. Unlit torches with their design taken from Super Mario Galaxy also appear. Red, Green, Blue and Pink Shy Guys surround the court. Wario Dunes is the default court when one plays the Flower Cup tournament.
Wario Dunes has a very similar layout to the Wario Court in Mario Tennis 64. Both are set in the desert and both are notable for having very low ball speed and bounce. Both also feature a remix of the city stage theme from Wario Land 3 as background music.
"A desert court surrounded by ancient ruins."
Names in other languages
||Desierto de Wario