Þingvellir National Park is a UNESCO World Heritage Site located in Iceland. It is known for its unique geological features, including the rift valley formed by the separation of the North American and Eurasian tectonic plates. The park is also home to the largest natural lake in Iceland, Þingvallavatn, and offers stunning landscapes with waterfalls, lava fields, and diverse flora and fauna. Historically, Þingvellir holds significant importance as the site of the world's first parliament, the Althing, established in 930 AD. Visitors can explore various hiking trails, enjoy scenic views, and learn about the rich cultural heritage of the area.