I'm not surprised, who would want to be buried with a view of a sewage aeration pond? Oh, and don't even mention the smell.

"Apparently when they started the earth works for the sewer plant back in 1973, they found the headstone and footstone collapsed in laying on the ground," remarks Dunley who admits to paying "his respects to Henry Dunkley (1802-1842)" on his daily rounds at the Gunning Sewerage Treatment Plant.

My interest in Dunkley's (sometimes spelt Dunckley) grave piqued when driving past the sewerage works several months ago. Through the security wire fencing, I noticed what appeared to be a headstone perched just above the ponds chock-full of liquid waste.

I initially thought, it couldn't be, could it?

"This is the only plant of its kind with a 24-hour operator," jokes Dunley, while brushing flies away.

The inscription on Dunkley's grave poignantly reads "cruelly and barbarously murdered by his wife and manservant on 13 September 1842. Aged 40 years he was cut down in his prime by a treacherous woman's hand."

While the inscription bears testament to one of the colony's most brutal murders, it doesn't explain why poor Dunkley ended up with such an unfortunate final resting spot.

Eager to find out more about his grisly death at the hands of his wife Lucretia and her lover Martin Beech, I track down Keith Brown, research officer with the Gunning and District Historical Society. Having heard many rumours about the death of Dunkley, the 90 year-old former career diplomat and deputy secretary to two governor generals recently penned an authoritative booklet The Day that Dunkley Died: Murder and Retribution in Colonial Gunning (2014) in which he busts some of the myths around the macabre murder.

"Some say that after he was bludgeoned to death with an axe that his shallow creek-side grave was either interfered with by a feral pig or that his corpse was washed several kilometres downstream," says Brown as we bump along the farm track that leads to the location of his murder.

"While he was definitely hacked to death by an axe, my investigations show that his body was found where Beech had buried it, just near this creek," says Brown pointing towards Meadow Creek which meanders through the rolling hills of Wagahrallah, a sheep and cattle run owned by Lawrie Nock for the last 42 years.

"The day we bought the property we heard all the stories about Dunkley and all the folklore associated with it," reveals Nock adding "when you are out here at night, coming back in the dark from moving the cattle you don't feel frightened but there is a feel about the place."

While the slab hut where Dunkley met his grisly end is yet to be discovered, he does show us the crumbling ruins of an old house that he believes "was probably built shortly after Dunkley's death to help sell the property."

It's just on dusk. The crows cry mournfully and the exotic plantings have over the old homestead almost triffid like in their stranglehold of the ruins.

"I don't feel any spiritual sensitivity like others do," deadpans the straight-laced Nock, adding "one person about 35 years ago went into the ruin and said "oh you can feel something terrible happened here."

"Several years ago I searched without luck for the slab-hut where Dunkley was murdered with a metal detector hoping it'd pick up coins or something similar," says Brown, adding, it's possibly on other side of the creek which is and damn hard to get at."

Hanged on October 16, 1843 at Berrima Gaol, according to Brown "the bodies of Beech and his accomplice are buried inside the walls of the prison apparently standing up so they could never rest in peace."

The Morning Chronicle of October 21, 1843 reported "both prisoners exhibited the like apathy upon the scaffold, and died as they had lived, hardened and unrepentant".

While the burial site of the dastardly duo is definitely inside the gaol the exact location cannot be confirmed, but Brown believes the two crosses in a sandstone block provide a clue.

"In the process of being hanged Lucretia aborted a foetus and it is likely those two crosses indicate the burial spot of Lucretia and her unborn child," explains Brown, adding, "perhaps a geophysical search may one day provide an answer to this."

Now back to the poor victim's final resting place.

"Certainly at that period of time, it was not uncommon for suicides to be buried by the Police in unconsecrated ground without the presence of clergy [or family members]," says Brown, adding "but Henry Dunkley was not a suicide."

One suggestion, according to Brown is that "Dunkley's body was far too damaged for burial in the local cemetery and buried in what was originally the police horse paddock." In the early 1970s with the grave long forgotten and hidden under blackberry brambles, the council decided it was the best spot for the sewerage treatment plant.

There are thousands of unmarked and unkempt graves in regional Australia. However the notoriety as a result of its unique position will no doubt ensure that Dunkley's grave doesn't become one of those.

RIP Henry Dunkley.

While the general location where Dunkley was murdered is on private property, there are several other points of interest integral to this case that the history buff can visit.

Old Berrima Courthouse Museum: Lucretia Dunkley was first woman hanged in Australia. Since then some believe her ghost has appeared at Berrima Court House pleading innocence on grounds that she only wanted happiness. The trial of Lucretia Dunkley and her lover Martin Beech also makes for an interesting audio and lightshow which can be viewed in the courtroom. More: www.berrimacourthouse.org.au

The old Goulburn Brewery: It was at this once flour mill that over a week after Dunkley's disappearance, police suspicious of Beech detained him while he was delivering wheat with Lucretia. It is one of the oldest breweries in Australia still producing traditional beer. 23-31 Bungonia Road Goulburn. For opening times: www.goulburnaustralia.com.au

Dunkley's grave: Due to safety concerns Dunkley's grave isn't accessible to members of the public. If, however, you walk up to the fence of the Gunning Sewerage Treatment Plant (near corner of Biala and Wombats streets) you can see the distinct headstone of Dunkley's grave overlooking the race-track style aeration channel. The original headstone was arranged by Dunkley's brother, David and the brass plaque added by the Gunning and District Historical Society in 1988 to preserve the wording engraved on the headstone.

Did you know: Following their death and prior to burial the skulls of Lucretia Dunkley and Martin Beech were removed from their bodies and passed on to surgeon William Ramsay to be studied. Popular at the time, phrenology, the science by which character can be read by examining the skull has since been discredited. The skulls are still held this day by the Australian Museum.

The book: The Day that Dunkley Died: Murder and retribution in Colonial Gunning (Keith Brown, 2014) is available from the Gunning & District Historical Society (www.gunninghistory.blogspot.com.au), and the Gunning Newsagency.

Clue: Passed by thousands of motorists every day.

Degree of difficulty: Medium.

Last week: Congratulations to Suzanne Vidler of Mawson who correctly identified last week's photo, sent in by Debbie Cameron of Ainslie as the Australian National University's (ANU) heritage-listed Llewellyn Hall. Opened in 1976, by the then Governor General Sir John Kerr, the School of Music building is a grand architectural statement in the 'Brutalist' style. The site had been the oval for the old Canberra High School and was chosen for its ability to link the ANU campus with the Canberra city centre.

How to enter: Email your guess along with your name and address to timtheyowieman@bigpond.com. The first email sent after 10am, Saturday 9 December, 2017 will win a double pass to Dendy.