As the Kingston Penitentiary opens its doors to paying visitors curious to see where some of the most notorious criminals in the country once lived, CTV Ottawa's Leah Larocque got a first-hand look at the former maximum security prison.

Tours of the penitentiary in Kingston, Ont., run until Oct. 29. 

For $25, visitors will get an inside look of the former prison, touring the areas where inmates ate and slept. The 90-minute tour also takes visitors to significant outdoor areas of the compound, such as the visitors' quarters.

In this fenced-off area, people visiting inmates were permitted to stay on the prison grounds for up to 72 hours, every two months.

While the tours are led by summer students, there are also former correctional officers who worked at the penitentiary at multiple points along the tour, reports CTV Ottawa's Leah Larocque.

The former correctional officers share interesting anecdotes and highlight specific points of interest, such as a location where some prisoners once tried to escape, Larocque said.

First opened in 1835, the penitentiary predates Canada's confederation and was designated a National Historic Site in 1990. It was officially closed in 2013.

While in operation, it housed some of the country's most notorious convicts, including Paul Bernardo, former colonel Russell Williams, and serial killer Clifford Olson.

The last time public tours of the prison were offered in 2014, all 18,000 tickets sold out in an hour. This round of tours is expected to bring in more than $6 million to the local economy.

With a report from CTV Ottawa's Leah Larocque