Clues are being sought to the location of a former isolation hospital used for the treatment of patients with infectious diseases in Lochaber.
Highland Council's Historic Environment Record team is hoping to update its records on what was known locally in Fort William as the "fever hospital".
It was thought to have been used during the early part of the 19th Century.
Two sites have been suggested so far - one behind the Belford Hospital and another on an area called An Aird.
The isolation hospital may have treated victims of scarlet fever.
Caused by a bacterial infection, it gives sufferers a sore throat and a red rash. It can be treated with antibiotics.
One-eyed dog
Buildings which once stood on the suggested site at the Belford Hospital were used as a first aid post during World War II before being converted into a maternity ward in the 1950s.
The Aird site, meanwhile, almost became part of the town's dump in the 1970s.
Abandoned buildings there provided shelter for a homeless man and his one-eyed dog, according to local information supplied to the Historic Environment Record.
Fort William also had a separate smallpox hospital on the Aird and this, according to the council team, may be being confused for the isolation unit.