 The Selle enters from the northwest of Amiens, with two arms (including the Haute Selle) passing behind the Unicorn Stadium, the exhibition park, the megacity and horse racing track, then passing the end of the "Promenade de la Hotoie" and the zoo of Amiens, and to the right of the water treatment plant, in front of the island Sainte-Aragone, opposite the cemetery of La Madeleine in Amiens.The city developed in a natural narrowing of the river at the level of the , due to the advance of the rim of the Picard plateau in Saint-Pierre (ford crossing).The Amiens citadel is built on this limestone butte and "Rue Saint-Pierre" is a slightly inclined path to leave the city from the north.