There's no need to go to the cinema to see the new Indiana Jones in order to get a taste of archaeological excitement, instead simply set your compass for Dockyard.

A man-made tunnel thought to date back at least to the early years of the 1800s has just been discovered beneath the historic Casemates Barracks. The tunnel is lined with Bermuda stone and has an arched ceiling. It is tall enough for a person to stand inside.

The purpose of the tunnel and its exact date of construction is still to be determined through a thorough archaeological investigation. Bermuda's archaeologist Dr. Ed Harris last week led the adventure into the darkened corridor that predates the 1840s building above it.

A team from insurance and reinsurance company XL were taking part in their company's 'Global Day of Giving' helping to demolish the last vestiges of the former Casemates Prison that was created within the much older barrack buildings when a small hole appeared in the ground beneath one of the excavators being used.

A further investigation by Dr. Harris, director of the Maritime Museum who was supervising the work, revealed the extent of the previously unknown tunnel.

"The tunnel is about 60-feet long, or about twice the width of the building, and is constructed of Bermuda stone, including an arched ceiling with ventilation holes.

"The mounds of rubble that partly blocked the tunnel came through ventilation holes and consisted of soil, brick and small stones," said Dr. Harris, who created the world famous Harris Matrix system that is used around the globe for recording archaeological discoveries. "The tunnel was clearly designed to be used as a passage by people and is high enough to walk in comfortably. The presence of the ventilation holes suggest that the tunnel would have been under open ground, which today is partly covered by a major building of the 1840s."

Making a "preliminary interpretation", Dr. Harris said the tunnel may be the only known remnant of the first defences at Dockyard and may be related to the first fortifications on the southern side which called for a defensive ditch and a Martello Tower similar to the one that stands at Ferry Reach National Park.

"The XL volunteers not only gave, but discovered a feature of the Dockyard that may be of global interest in the history of Bermuda's fortifications," he added.