Zadrna (German: Zieder) is a river in Lower Silesian Voivodeship in southwestern Poland, a right tributary of the Bóbr. It rises in the Góry Krucze range of the Central Sudetes near the village of Błażejów, close to the border with the Czech Republic.

Zadrna
Zadrna River in Kamienna Góra
Location
CountryPoland
Physical characteristics
Source 
 • locationGóry Krucze near Błażejów
 • coordinates50°39′40.5″N 16°1′44.1″E / 50.661250°N 16.028917°E / 50.661250; 16.028917
 • elevation600 m (2,000 ft)
Mouth 
 • location
Bóbr in Kamienna Góra
 • coordinates
50°47′12″N 16°2′21″E / 50.78667°N 16.03917°E / 50.78667; 16.03917
 • elevation
440 m (1,440 ft)
Length16 km (9.9 mi)
Basin size112 km2 (43 sq mi)
Basin features
ProgressionBóbrOderBaltic Sea