Major excavations on Spike Island have uncovered a tunnel and a previously unknown crafted spiral staircase which are believed to have been part of a fort built there in the 1790s.
Further excavations are planned on the island in the coming days and weeks as experts believe only about 30% - 40% of the underground fortifications are currently accessible.
Spike Island manager John Crotty said a number of blocked up tunnels are to be reopened “and who knows what further exciting finds will be made in them".
Last Friday, maintenance workers on the island, under the supervision of the heritage officer, took away a bricked-up wall at the entrance of a tunnel which leads towards the defensive walls of the fort overlooking the moat.
“We never expected to find a doorway leading off it and behind that was a beautifully crafted stone spiral staircase which leads to the top of the fort's walls,” Mr Crotty said.
The door leading to the spiral staircase is about a quarter of the way down the 30m-long tunnel.
The tunnel is intact and inside it they have found a lot of empty wine bottles and some which were still half full.
In addition, they have found a number of bones, which Mr Crotty said at first caused some alarm as they thought they may have been human.
However, subsequent examination by experts revealed they were animal bones.
Barra O’Donnabhain, an archaeologist from UCC, visited the island yesterday (Wed) to view what has been uncovered so far.
“He told us the wine bottles were probably late 18th century or early 19th century. We intend to display some of them in the museum,” Mr Crotty said.
Next week they plan to open up another bricked-up tunnel on the opposite side of the fort and from then on open up other underground areas which have also been blocked off over the years.
“We are only beginning to scratch the surface on this project. We believe that only 30% - 40% of the underground areas which exist on the site have been opened up. So there's a lot there to be rediscovered,” Mr Crotty said.
Work on the coastal defences, at what was then known as Fort Westmoreland, was overseen by a colourful character, General Vallency.
“He had four wives and 14 children. The wives came one after the other and he was last married in his 70s. He oversaw all the major coastal defences works in the Cork harbour area at the time,” Mr Crotty said.
The island has over 1,300 years of history. It was first a monastic settlement, but became a home to smugglers, a fortress and was once the largest prison in the world.
In the 1980s it became a prison again, mainly for young offenders, but following a riot was closed.
It was handed over by the Department of Justice to Cork County Council a few years ago and since then the local authority and Fáilte Ireland have funded its development as a tourist attraction.