Visitors have a chance to tour the historic New Plymouth prison before it is finally shut down.
The last prisoners have been moved from the 140-year-old jail which will be closed on Thursday.
Corrections Service regional manager Terry Buffery said the building had reached the end of its life.
He says cells in the old part of the prison are the smallest in the country at two metres by three metres.
Mr Buffery says it is inhumane to house prisoners in such a small space and with poor lighting and ventilation.
Fittings have been dismantled and sent to other prisons.
People are able to tour the jail on Saturday. The formal closure on Thursday will include a blessing of the site.