Nilo Syrtis (or Nilosyrtis) is a region just north of Syrtis Major Planum on Mars, at approximately 23°N, 76°E and an elevation of −0.5 km. It marks a region of transition (a crustal dichotomy) between southern highland and northern lowland terrain, and consists of isolated peaks and mesas. On average, the drop in elevation between the two terrains is 5,500 meters (18,000 feet).