Gambling tokens, buttons and carved clay pipes uncovered in an archaeological dig at Port Arthur have shed light on the pastime of convicts.

The dig is taking place behind the penitentiary building and is one of the biggest excavations to occur at the World Heritage site.

Dr Richard Tuffin is the project archaeologist and has been working with his team from across Australia in the rain, wind, sleet and shine.

The yards under excavation were where the convicts spent their time when not undertaking work.

The dig has been taking place behind the penitentiary building which was just a grassed area before. ( 936 ABC Hobart: Paul McIntyre )

Similar to exercise yards in modern-day prisons, the yards were essentially to help keep the men in good physical condition.

"The finds are amazing," Dr Tuffin said.

"The yards went through two distinct phases.

"The key thing about this space was keeping the convict population healthy, as if they are healthy then they can work."

Flushing toilets for convicts

During the first phase the yards featured shelter sheds for the men complete with fireplaces.

In the 1860s a second period of development saw toilets and washing areas erected for the prison population.

One of the most curious aspects of the site was the advanced nature of the facilities.

"There is a form of flushing toilets, which for the 1860s is very early," Dr Tuffin said.

"You don't normally get that form of hygiene and treating waste until the 1880s, even in towns like Hobart."

Smoking pipe marking the Battle of Waterloo

Unlike modern prisons, convicts in the mid 19th century were allowed to smoke.

"One thing we've found are a lot of clay tobacco pipes," Dr Tuffin said.

"We know they were smoking here."

Both sides of a clay pipe featuring Napoleon and Wellington was found at the site. ( Port Arthur Historic Site Management Authority: Michael Smith )

Many of the pipe stems uncovered are characterised by the teeth marks of the owner.

Some of the fragments were decorated which help to pinpoint a likely timeline.

"We have one we think is linked to the American Civil War," Dr Tuffin said.

A unique discovery was a section of clay pipe thought to be commemorating the 50-year anniversary of the Battle of Waterloo.

"We have [a pipe] with Napoleon on one side and Wellington on the other," Dr Tuffin said.

Evidence of gambling despite a ban

All up, the yard has revealed about 1,600 finds, including wooden buttons and gambling paraphernalia.

"The most welcome find has been the quantity of gaming tokens," Dr Tuffin said.

Made from a range of different materials including lead, slate and ceramics, the tokens unearthed have been both circular and square in appearance.

"The interesting thing about these is they're all very rough," Dr Tuffin said.

Dr Richard Tuffin and his team have been at the archaeological dig since January and expect to finish in June. ( 936 ABC Hobart: Paul McIntyre )

Gambling was not allowed, so convicts would have had to smuggle the material into the yard without the guards seeing them.

"They speak of power and the hierarchy that would have been happening," Dr Tuffin said.

"You wouldn't have messed with the guy who had control of this black-market economy."

Once the dig is finished, the area will be reconstructed as an interpretation area for visitors.

"We want to put the penitentiary in context," Dr Tuffin said.