The six-episode 'revival' of a former documentary series covers baffling, bizarre and murderous incidents from France to America.

The Shoalhaven is not without its own unsolved mysteries. Below are six of them.

If you have any information that could help find a missing person, or solve a crime, please call Crime Stoppers on 1800 333000 or use the Crime Stoppers online reporting page: https://www1.police.nsw.gov.au/.

Information you provide will be treated in the strictest of confidence.

Billy Blue is a 19th century legendary character from the Shoalhaven.

An Indigenous man, Billy Blue made regular trips to Terara and paid his way with gold nuggets, the source of which has never been discovered.

The name of Billy Blue is also a mystery, as it does not appear in official documents, however, according to an article written by Bill Morton for the South Coast Register's 'Back to Shoalhaven Week' feature in 1926, Billy Blue was known to Nowra's first mayor, Henry Moss.

The source of his gold nuggets has been the subject of much speculation by clairvoyants, geologists and locals hoping to get rich quick - but no one ever found it.

It's possible the Shoalhaven is home to a hidden goldmine, if anyone can figure out where it is.

Kathleen Harris, aged 16, was last seen at her home in Huskisson by Rebels bikie associate Clinton Hanlon about 9pm on May 31, 1999.

She had planned to meet with friends the following day but never arrived.

Her personal belongings, including her purse and keys, were located in her home, and family and friends have not heard from her since she went missing.

The Costa-Rican born teen had moved to Australia with her father a few years before her disappearance.

Police are treating her disappearance as suspicious and have not ruled out that Kathleen may have been murdered.

Detective Sergeant Paul McCann told the court at a 2013 inquest he believed Mr Hanlon had some involvement in her disappearance.

There is a $100,000 reward offered.

She is described as 160cm, a slim, brown hair and olive complexion.

Kathleen would now be aged 36.

Shoalhaven time-capsule enthusiasts have been largely unsuccessful over the years.

Most recently, an extensive search, including ground radar and excavation equipment, failed to find a time capsule buried near the Captain Cook Bicentennial Memorial, on the southern bank of the Shoalhaven River.

Part of the official opening in 1971 included the placing of a time capsule near the structure.

The arch was demolished in early June with Transport for NSW attempting to find the capsule and return it to Shoalhaven City Council and the Shoalhaven Historical Society.

Unfortunately, despite an extensive search no trace of the time capsule could be found.

There is also supposedly a time capsule hidden in the sandstone brickwork of the main wall of the Nowra War Memorial Gates at the entrance to the Nowra Showground at the intersection of West and Junction streets.

Another time capsule was supposedly in the brick fenceline in front of the Nowra Showground pavillion. It could not be found when renovation works were undertaken in the area a couple of years ago.

Another time capsule understood to be placed in the star garden area of the Nowra East Public School could not be located when attempts were made to find it for the school's 50th anniversary.

Is there a serial time capsule thief about? Is something more mysterious at work? Or are we just not very good at recording where to dig?

Kiama nurse Jackie-Lee Walsh was last seen by her boyfriend when she drove him to work at 8am on Friday, April 14, 1989.

She never made it to an appointment with her accountant that morning, or lunch with a girlfriend.

A pool of blood found in her red Torana, parked outside Warrawong's Open Hearth Hotel six days later, convinced police Ms Walsh suffered a savage death.

They believed she was either viciously beaten or had her throat cut, then was bundled into the boot where she bled to death before being dumped.

Police later discovered Ms Walsh had gone to a house in Moss Vale to buy drugs on the Friday and left at 3pm to meet another friend in Kiama.

But she was never seen again

In the early 1980s a number of Shoalhaven residents, including then Mayor Harry Sawkins, Aldermen Gordon Ravell and Max Atkins, South Coast MP John Hatton received small icons resembling owls.

Former Shoalhaven Mayor, Max Atkins said he received an owl icon in an anonymous envelope delivered to his council "pigeon hole".

Most of the recipients were involved in local politics, particularly the local council.

Even Shoalhaven and Nowra News newspaper editor Jim Baker received one of the mysterious objects.

Many people attached sinister interpretations to the discovery of the icons, including at the time, Mr Ravell's sister, Mrs Alchin.

Mr Ravell died in a tragic accident in December 1986.

His burnt out four-wheel-drive vehicle was located 150 metres down the side of a steep slope on an isolated stretch of road near Burrier Pumping Station, west of Nowra, with his naked body 20 metres away.

Coroner Brian McKeough did not to allow any published press reports of parts of the inquest hearings, and ruled evidence introduced into the inquest concerning alleged death threats and the distribution of so-called Voodoo symbols, was irrelevant and without substance.

The meaning behind the owl icons has never been discovered.

David Lowe, 76, was found dead in his Sussex Inlet home on August 2, 2002.

Mr Lowe, known as Santa Claus because of his snow white beard and kind manner, died from head injuries inflicted by a blunt object.

He was last seen alive about 7am when he bought a newspaper from his local newsagency.

Investigating police were particularly interested in information about Mr Lowe's car, a silver Mazda 626 sedan, registration XWN 162, found on the Princes Highway several hours after the murder was discovered.

The car was found at the Wandandian car park at the intersection of the highway and Sussex Inlet Road.

The car, and a number of other items, had been subjected to DNA and fingerprint tests, and other forms of scientific analysis.

Police do not believe Mr Lowe had driven the car to the car park.