Creating a water highway connecting the Potomac and Ohio rivers brought the C&O Canal Company many obstacles, and one of the most difficult was navigating around Great Falls, where the Potomac River plunges more than 41 vertical feet. To carry boats safely past the river, the company built six closely spaced locks. In the 1870s, Great Falls became a popular destination for city-weary Washingtonians, and the lockkeeper house was enlarged twice to serve as a hotel and tavern. Today the area continues to attract tourists and local residents for its natural beauty, recreational opportunities, and historic significance, and the Great Falls Tavern, also known as the Crommelin House, houses the C&O Canal Visitors Center. A photograph taken in the 1920s at the Great Falls pedestrian bridge reflects the area's growing tourist business.