Päijät-Häme is a region in Southern Finland south of the lake Päijänne. It borders the regions of Uusimaa, Kanta-Häme, Pirkanmaa, Central Finland, South Savo and Kymenlaakso. The biggest city in the region is Lahti.

Uusimaa is a region of Finland. It borders the regions of Southwest Finland, Tavastia Proper (Kanta-Häme), Päijänne Tavastia (Päijät-Häme), and Kymenlaakso. Finland's capital and largest city, Helsinki, along with the surrounding metropolitan area, are both contained in the region, and Uusimaa is Finland's most populous region. The population of Uusimaa is 1,734,000.