Mazowsze is the largest region of Poland, located in east-central Poland. It covers over 35,000 square kilometers and has a population of over 5 million people. Some key features and sites of interest in Mazowsze include the beautiful Kampinos National Park, nine landscape parks, 171 nature reserves, historic castles and churches, and the Polish capital of Warsaw. Mazowsze has a rich cultural heritage and is home to many remnants of the past, including noble mansions and the birthplace of Frederic Chopin.