Valdštejnsko is a village in Semily District, in the Liberec Region, Czechia. Valdštejnsko lies at 269 m above sea level, 3.6 km from the Giant mountains. The nearest city is Jablonec nad Nisou, 17.5 km to the north. Among the landmarks around are Kost Castle (9.5 km), Trosky Castle (7.0 km) and Valdštejn Castle (1.4 km). Among the natural features are Maškova zahrada (2.5 km) and Postojna (3.7 km).