Gamaches is situated on the D1015, on the banks of the Bresle River, the border with Seine-Maritime, some 18 miles (29 km) southwest of Abbeville.
Huge lakes to the west of the town are a paradise for naturalists, anglers and water sports enthusiasts.
1471 Louis XI and the Burgundians wage war in and around the town. A year or so later, Charles the Bold ravaged Picardy in the continuing battle with Burgundy. The plague decimated not only the troops but also the local populace.
Gamache has, for a long time, been linked with the manufacture of glass.