When archaeologists excavated a 1,700-year-old settlement in central England, they got a literal whiff of the past after accidentally breaking open eggs dating back to the Roman occupation of Great Britain.

As the researchers report in a new monograph published by Oxford Archaeology, the team unearthed the chicken eggs at Berryfields—an ancient community located along a Roman road called Akeman Street—while conducting excavations between 2007 and 2016.

According to a press release, the eggs were among a trove of rare items recovered from a waterlogged pit. The gaping hole preserved organic items that would have otherwise deteriorated in the soil, including a rare wooden basket, leather shoes, and wooden vessels and tools.

Three of the four eggs were intact upon discovery, but two cracked during retrieval, releasing a pungent rotten egg smell. One of the fragile vessels emerged from the pit intact and is now being hailed as the only complete Roman egg ever found in Britain.

“There’s a very good reason it’s the first and only find in the U.K.,” dig project manager Stuart Foreman tells the Independent’s Chiara Giordano. “In a pit that has been waterlogged for thousands of years you get things that would never survive in a dry environment. But it’s incredible we even got one out. They were so fragile.”

So, why were the eggs in the pit in the first place? Per the press release, archaeologists think the pit was originally used for malting grain to brew beer between the second and third centuries. By the end of the third century, however, the pit had been transformed into a wishing well of sorts, with people tossing in coins or other objects as small sacrifices to the gods.

Speaking with the Times’ Mark Bridge, archaeologist Edward Biddulph says the eggs and a bread basket found in the pit may represent food offerings tossed into the well as part of a funeral procession or religious ceremony.

“Passers-by would have perhaps stopped to throw in offerings to make a wish for the gods of the underworld to fulfill,” he adds. “The Romans associated eggs with rebirth and fertility, for obvious reasons.”

According to Biddulph, archaeologists have found chicken bones and broken eggshells in Roman graves before, but the Berryfields find is the first complete specimen of its kind unearthed in Britain to date.

“The eggs may have been carried within a funerary procession,” says Biddulph. “The procession stopped at the pit, where a religious ceremony took place and the food offerings were cast into the pit for the spirits of the underworld or in the hope of rebirth.”

The well was abandoned during the fourth century, and the area around it was later converted to agricultural land, reports BBC News.

As the Independent’s Giordano writes, the only other intact Roman era chicken egg known to survive today was found grasped in the hand of a child buried in the city of Rome back in 2010.

For now, the British egg is safely enconsced in an acid-free tissue paper-lined box housed at Oxford Archaeology’s headquarters. It will soon go on view at the local Buckinghamshire County Museum.

According to a separate press release, the Berryfields team found traces of other trades and crafts in the area, as well as evidence testifying to the importance of livestock, and in particular horses. The archaeologists also found evidence of funerary activity, including a site that may have been used as a funeral pyre.