Record Data Feature Ref. Largest canyon 4000 km long, 200 km wide Valles Marineris, Mars [1] Tallest mountain 22 km (13.6 mi) Rheasilvia central peak, Vesta [2][3] Tallest volcano 25 km (15.5 mi) Olympus Mons, Mars [4] Tallest cliff 20 km (12.4 mi) Verona Rupes, Miranda, Uranus [5] Largest impact crater 2,700 km (1,700 mi) North Polar Basin, Mars [6]