Geographically, it is surrounded by the Amöneburg Basin on the southeast edge of the Burgwald (a low mountain range) about 15 km east of Marburg on the rivers Ohm and Wohra.

Besides the main centre of Kirchhain with about 8,300 inhabitants, 12 further constituent communities share another 8,900 people: In prehistoric times a network of long-distance and connecting trails crossed back and forth over the area where the town of Kirchhain was later to be founded.

The high point of the expansion of settlement was in the early Iron Age (5th century BC).

As of the 13th century, the landgraves of Hesse further upgraded Kirchhain as a Hessian bulwark against Mainz's centre of Amöneburg so that they could control the region.

Kirchhain likewise had to put up with such troubles in the Seven Years' War as its good traffic connections once again led troops to the town.