Archaeologists in the U.K. were shocked to learn that a 1,700-year-old Ancient Roman egg discovered in Aylesbury, Buckinghamshire still had a yolk inside, according to reports.

It's thought to be the only time a centuries-old chicken egg found with its insides preserved.

The discovery of the egg was announced in December 2019, after archaeologists with Oxford Archaeology completed a dig in Aylesbury between 2007 and 2016.

The experts found a basket containing four eggs in a waterlogged pit, which they believe may have been used as a "wishing well." However, when the eggs were removed from the environment, three of the eggs broke, and they let off what was described as a "potent stench."

The remaining egg survived, and according to the BBC, it underwent a micro-CT scan that revealed what was inside.

"We were absolutely blown away when we saw the contents in there, as we might have expected them to have leeched out," he said.

The dig took place before the development of housing at Berryfields in Aylesbury, and along with the eggs, archaeologists found dozens of coins, shoes, wooden tools and what was described as a "very rare" basket.

Biddulph said at the time of the announcement that the "wishing well" may have operated similar to modern-day wishing wells.