Kaltenbronn, Nature reserve in Northern Black Forest, Germany

Kaltenbronn is a combined nature and forest reserve of about 1,750 hectares in the northern Black Forest, established in 2000 as the first of its kind in Baden-Württemberg. It joins two separate nature reserves two kilometres apart: the Wildseemoor with Wildsee and Hornsee in the northeast, and the Hohloh plateau with Great and Little Hohlohsee and Breitlohsee in the southwest. Elevations run from 680 m in the Brotenautal to 989 m on the Hohloh.

The Wildseemoor boundary between Gernsbach and Bad Wildbad follows the old border between Baden and Württemberg. On 25 October 1927, one day after the Baden nature conservation office was set up, the Baden minister of culture protected about 70 ha as the Wildseemoor nature reserve; in 1928 Württemberg designated about 108 ha of Bannwald on its side. In 1939 and 1940 the reserves were extended across the border, and the combined Kaltenbronn nature and forest reserve was established by ordinance of 22 December 2000.

The border running through the Wildseemoor follows the old frontier between Baden and Württemberg, and the reserve's protection began on the Baden side: on 25 October 1927 the Baden minister of culture designated about 70 hectares as the Wildseemoor nature reserve, one day after the state nature conservation office was set up. Since 2008 the Infozentrum Kaltenbronn in the hamlet of Kaltenbronn has housed a nature museum with events on the area.

The reserve lies on both sides of the L 76 state road, with the Wildseemoor and its lakes northeast of the road and the Hohloh plateau moors southwest. The Kaltenbronn information centre in the hamlet of Kaltenbronn, open since 2008, has a nature museum and is a starting point for trails. Elevations run from 680 m in the Brotenau valley to 989 m on the Hohloh, so weather changes quickly.

The Wildsee and Hornsee are not connected: they lie about two kilometres apart within the Wildseemoor, which at 187 hectares is the largest high moor in the Black Forest. The moor straddles the old border between Baden and Württemberg, which runs through it.