Gamaches is a commune located in the Somme department within the Hauts-de-France region of northern France. Situated on the banks of the river Bresle, which marks the border with Seine-Maritime, the town lies along the D1015 road. It is positioned approximately 18 miles or 29 kilometers southwest of Abbeville, placing it in a distinct geographical zone defined by its riverine setting and regional connectivity.

The area has a long history of conflict and resilience. In 1471, Louis XI and the Burgundians waged war in and around the town, leading to further devastation when Charles the Bold ravaged Picardy a year later. The plague decimated both the troops and the local populace during these turbulent times. Later industrial development began in earnest when glass bottles started being manufactured in Gamaches in 1922, marking a significant economic shift for the community.

The town features notable architectural and historical landmarks that define its character. Visitors can explore the thirteenth-century church of Saint-Pierre and Saint-Paul, which displays flamboyant gothic tower elements resulting from successive architectural influences over the centuries. The old railway line, which was opened in 1872 and closed in 1993, remains a part of the local heritage, alongside the prominent war memorial that stands as a testament to its past.

Gamaches offers significant appeal for nature enthusiasts due to its unique landscape features. Huge lakes situated to the west of the town provide a paradise for naturalists, anglers, and water sports enthusiasts. These aquatic environments attract visitors seeking outdoor recreation and ecological observation, making the natural surroundings a central component of the town's visitor experience and cultural identity.

As of 2023, the population of Gamaches is recorded at 2,397 residents. The local economy has historically been supported by industries such as glass manufacturing, which began in the early twentieth century. Access to the commune is facilitated by its location on the D1015 road and its proximity to Abbeville, providing transport links that connect this northern French community to the broader regional network.