The current Portland Old Low Lighthouse was established in October 1867 and was designed to work as a leading light with the Old High Lighthouse. Both towers exhibited a fixed light; by keeping the lights in line, mariners were guided between Shambles bank and the shore.
Both the Old High and Old Low Lighthouses replaced previous towers that were built in 1716.
Both lighthouses were discontinued in 1906 when they were replaced by the current Portland Bill Lighthouse.
The lighthouse is now a bird observatory and hostel.