Marlow Lock is a lock on the River Thames located in the town of Marlow, Buckinghamshire, England. It was built in 1773 and is part of the Thames Navigation system, which allows boats to travel smoothly along the river. The lock raises and lowers water levels, enabling vessels to navigate through different sections of the river. The lock features a traditional design with wooden gates and a control house. It is operated by the Environment Agency, which manages the river's navigation and maintenance. Marlow Lock is a popular spot for both boaters and visitors, offering scenic views and access to nearby walking paths.