Uranius Tholus is a volcano on Mars located in the Tharsis quadrangle at 26.52° north latitude and 262.43° east longitude. Uranius Tholus is part of the Uranius group of volcanoes and lies north of the larger Ceraunius Tholus. (wikipedia entry)
A tholus is a small domical mountain or hill. On Mars they are named after the nearest named albedo feature on the Schiaparelli or Antoniadi maps.