Portland Bill should not be confused with the Isle of Portland. The Bill has three lighthouses; it is an important way-point for ships passing the headland and its tidal race. The current lighthouse was refurbished in 1996 and became computer-controlled; a visitor's centre giving information and guided tours of the lighthouse was built nearby. Two earlier lighthouses stand further inland.
Portland Ledge is an underwater extension of Portland Stone into the English Channel at a place where the depth of Channel is 20 to 40 metres. Tidal flow is disrupted by the feature; at 10 metres deep and 2.4 kilometres long, it causes a tidal race to the south of Portland Bill, the so-called Portland Race.