Päijänne Tavastia (Swedish: Päijänne-Tavastland) or, officially, Päijät-Häme is a region in Southern Finland south of the lake Päijänne. It borders the regions of Uusimaa, Tavastia Proper (Kanta-Häme), Pirkanmaa, Central Finland, South Savo and Kymenlaakso. The biggest city in the region is Lahti.