Namborn is located in a low wooded mountain range between the rivers Nahe and Blies in the Saar-Hunsrück Nature Park.

The highest elevation is the Friedenberg in Hirstein at 509 m; the lowest point is 298 m in Urweiler, where the Todbach leaves Namborn for St. Wendel.

Recognized natural monuments are the Wendalinushöhle (Wendelin's cave) in Baltersweiler, a historic Linden tree in Furschweiler, the Allerbach rock wall in Namborn, and 3 Oaks in Roschberg.

Since November 1983 there is a second reserve of 19.68 ha, Weiherbruch und Rohrbachwiesen , in the Namborn district and the neighboring community of Oberthal.

Numerous finds from the Celtic and Roman times, which were discovered or partially exposed in the communities of Baltersweiler, Eisweiler, Furschweiler, Bornerhof, Heisterberg, Hirstein, Namborn, and Roschberg, testify to an early settlement of the area.