The Outer Alster is a large lake located in the city of Hamburg, Germany. It is part of the Alster river system and covers an area of approximately 164 hectares. The lake is surrounded by parks and walking paths, making it a popular destination for both locals and tourists. Visitors can enjoy various recreational activities on the Outer Alster, such as sailing, rowing, and cycling along the scenic routes. The lake is also home to several events throughout the year, including boat races and festivals, contributing to its vibrant atmosphere in the heart of the city.