Gorey Castle has been reopened to the public after the completion of a £4.6m restoration project.
Some items for the restoration had to be airlifted to the site
The Lieutenant Governor Air Chief Marshal Sir John Cheshire presided over the opening ceremonies at the castle on Sunday afternoon.
It has taken more than six years to restore the 13th century building.
Building parts and large art exhibits had to be airlifted in by helicopter. The restoration work has included a new roof for the castle's Tudor Hall.
Architect John Williams said it was one of the most rewarding projects he has worked on.
"The thing I have learnt about the most is how difficult it must have been in the days when there were no helicopters, no cranes.
"It was all done by hand. We have had a lot of help from the RAF."
The reopening is the highlight of a three-week festival organised by Jersey Tourism featuring open gardens and special walks.