Complex sentence: The Washington Avenue Immigration Station was an immigrant processing facility in Philadelphia, Pennsylvania, United States located at the end of Washington Avenue at Pier 53 on the Delaware River, directly south of modern-day Penn's Landing waterfront district.
Split into simpler sentences: The Washington Avenue Immigration Station was an immigrant processing facility in Philadelphia, Pennsylvania, United States. It was located at the end of Washington Avenue on the shore of the Delaware River at Pier 53, the southern end of the modern-day Penn's Landing waterfront district.