Port Arthur was a natural prison.
It is on the Tasman Peninsula which is almost completely surrounded by the sea.
It is joined to the rest of Tasmania by a small narrow piece of land about 30 metres wide.
This is called Eaglehawk Neck.
The Neck had a fence, prison guards, and savage dogs to stop prisoners from leaving.
There was no contact between visiting seamen and prisoners.
Ships had to give the guards their sails and oars when they arrived to stop people leaving without permission.
A semaphore message system was also set up between Port Arthur and Hobart.
Messages could be sent in just 15 minutes.

Escape from Port Arthur was said to be impossible, like Alcatraz Island in the United States.
Some prisoners did try to escape.
One prisoner, George "Billy" Hunt, covered himself with a kangaroo skin and tried to get across the Neck.
The hungry guards on duty tried to shoot him to make an extra meal.
When he saw them pointing their guns, Hunt gave himself up.
He was whipped 150 times.
Bushranger Martin Cash successfully escaped along with two others.
Port Arthur was a natural prison. It is on the Tasman Peninsula which is almost completely surrounded by the sea. It is joined to the rest of Tasmania by a small narrow piece of land about 30 metres wide. This is called Eaglehawk Neck. The Neck had a fence, prison guards, and savage dogs to stop prisoners from leaving. There was no contact between visiting seamen and prisoners. Ships had to give the guards their sails and oars when they arrived to stop people leaving without permission. A semaphore message system was also set up between Port Arthur and Hobart. Messages could be sent in just 15 minutes.
Escape from Port Arthur was said to be impossible, like Alcatraz Island in the United States. Some prisoners did try to escape. One prisoner, George "Billy" Hunt, covered himself with a kangaroo skin and tried to get across the Neck. The hungry guards on duty tried to shoot him to make an extra meal. When he saw them pointing their guns, Hunt gave himself up. He was whipped 150 times. Bushranger Martin Cash successfully escaped along with two others.
Port Arthur, Tasmania