Nijmegen stands on a bit of a hill.
"Altitude" is a lofty word, but it's reasonably accurate relative to the Netherlands as a whole. You can see a bit of an elevation from a train while heading into town.
You can go down some hills fast enough on a bicycle to be a hazard. On the hill down from the Grote Markt toward the river, it would be easier to get off and walk than to apply brakes.
The normal manner of vertical measurement in Holland is not "altitude," but relationship to N.A.P.
The Normaal Amsterdams Peil is a measurement system based upon average local sea level that served as a standard from the 17th century in wider Europe.
This "normal Amsterdam level," since 2000 based upon the European Terrestrial Reference System, is officially represented physically by a pole embedded into the second Pleistocene layer of sand and located at city hall in downtown Amsterdam.
Nijmegen, at its highest point, is about 30 meters (100 feet) above N.A.P.
The river Waal, down the hill from the Grote Markt, is the larger of two distributaries of the Rijn (Rhine.) This river, a major waterway, forms the northern border of old Nijmegen at an elevation of about 8 meters. That's about 26 feet above sea-level, 80 miles (115 kilometers) inland.