This is a prison system secretly built by the French colonialists to detain political prisoners during the war of resistance.

Phu Tuong prison was built in 1940. It is located on Ton Duc Thang Street, Con Dao Island district. It is known as the "French tiger cage".

There are two layers of walls surrounding the secret tiger cage. Prisoners were blindfolded before being led here.
The tiger cage is located between camps 7 and 8, staggered, to keep it a secret from the outside. When going from camp 7, prisoners would think they were in camp 8, and when coming from camp 8 they would think they were in camp 7.
The entire tiger cage is 5,475 square meters, including cells of 1,408 square meters, and an empty space of more than 2,100 square meters.
The cells are 1.45m x 2.5m, including two secret areas, totaling 4 blocks, with 20 tiger cages each block, with stairs going up to the roof.
Guard could observe prisoners from above. They often tortured prisoners by poking them with iron-tipped sticks from above, pouring dirty water, throwing lime powder onto them, or not allowing them to bathe.
The tiger cages sometimes held thousands of prisoners, with 5 to 12 people locked in one room. They had to eat, sleep, defecate, and urinate on the spot, and had no space to lie down.
The diet for prisoners was so bad, they had to catch insects and rats to eat.
At the tiger cage area, there are also 60 separate cells without a roof, divided into four rows.
Phu Hai camp on Le Van Viet Street is the oldest and largest prison in Con Dao. It was built by the French colonialists to imprison revolutionary soldiers and Vietnamese patriots from 1862 to 1896. 
In order to deceive public opinion, the French colonialists built chapels, lecture halls, clubs, cafeterias, barber rooms and a medical room. 
There is a "special cell” where detained high-ranking officials were held such as: Ton Duc Thang, Pham Hung, Le Van Luong, Ngo Gia Tu...
A "rice mill" is surrounded by stone walls, with the ceiling made of black cloth, and only one door. Inside there are 5 mills. The mill could be pulled by 4-6 prisoners. Prisoners were chained together with a dumbbell weighing from 3-7kg.
There are 20 cells for “dangerous” prisoners who were always shackled.
Phu Tuong and Phu Hai prisons have become historical relics in Con Dao.
To get to Con Dao, visitors can choose Vietnam Airlines flights from Hanoi to Ho Chi Minh City and then use the Ho Chi Minh City - Con Dao route. Vietjet Air and Pacific Airlines plan to open this route also. 

Hoang Ha