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The Holey Jar restored.

The Riddle of the Roman Holey Jar – Why Would A Vessel Be Full of Holes?

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One of the most unusual pieces of Roman pottery around is a regular looking jar but for the feature of having many holes in its body. Since it’s restoration from a pile of broken pieces found in a storeroom, ascertaining the true purpose of this strange object has proved a harder puzzle to piece together. This jar is reputed to be the only known example of its kind and its exact function is still a mystery.

Hidden in Storage

The (modern) story of the Roman jar with holes began in a storage room in the Museum of Ontario Archaeology in Ontario, Canada. 180 pieces of pottery fragments forming a single vessel were discovered and painstakingly pieced together. The final product of this reconstruction work was a 40 cm (16 inches) jar riddled with holes, which left everyone puzzled as to what it was and how it may have been used.

The Holey Jar restored. (Katie Urban / Museum of Ontario Archaeology)

The Holey Jar restored. (Katie Urban / Museum of Ontario Archaeology)

Where Was the Jar Discovered?

The function of the jar is not the only mystery. It is unclear either as to where the object was actually from. The jar is most likely to have arrived in Canada from Great Britain. According to research done in the archives the jar was one of the artifacts given to the museum by the Welsh archaeologist, William Francis Grimes during the 1950s. The jar is assumed to have been excavated from a World War II bomb crater in London by Grimes. The site is located near the Mithraeum, a temple dedicated to Mithra, a deity adopted by the Romans from the East. Incidentally, the Mithraeum was also excavated under the direction of Grimes.

Ruins of the Temple of Mithraeum in London. (Gapfall / CC BY-SA 4.0)

Ruins of the Temple of Mithraeum in London. (Gapfall / CC BY-SA 4.0)

Nevertheless, one of the museum’s researchers, Katie Urban, has pointed out that it is not entirely certain that the jar was from the excavation of the WWII bomb crater as it does not appear on the list of artifacts given by Grimes to the museum. This, however, could be explained away by the fact that the jar was found in 180 fragments and that Grimes list was short on details.

Is It from Rome or Is It from Ur?

A bigger problem is that the storage room held not only artifacts provided by Grimes but also those contributed by another archaeologist, Charles Leonard Woolley, from his excavations in the ancient Mesopotamian city of Ur. From 1922 to 1934, Woolley served as the director of the joint expedition of the British Museum and the University of Pennsylvania to Ur. A portion of the artifacts discovered during the excavations were sent to the British Museum in London. In 1933, some of the objects were sent as a gift to the Museum of Ontario Archaeology. Therefore, there is a small chance that the jar came from Woolley’s excavation. If this were true, the jar have been made as early as 3000 BC, as opposed to the 2 nd/3rd century AD date if it were a Roman production.

Ruins in the Town of Ur, Southern Iraq. (M.Lubinski / CC BY-SA 2.0)

Ruins in the Town of Ur, Southern Iraq. (M.Lubinski / CC BY-SA 2.0)

A Glirarium?

As for the function of the jar, the best guess at the moment is that it was a glirarium, a special vessel used for storing edible dormice which were considered to be a delicacy by the Romans. The specific features of a glirarium are provided by the Roman writer Varro in his Res Rusticae. In Book III of his work, Varro states that “The potters make these jars in different shapes but with paths for the dormice to use contrived on the sides and a hollow to hold their food, which consists of mast, walnuts, and chestnuts. Covers are placed on the jars and there in the dark the dormice are fattened”. Additionally, the wall of the vessel “must be coated on the inside with smooth stone or stucco to prevent their escape”. An example of a glirarium can be seen at the National Archaeological Museum in Chiusi, Italy.

A glirarium exhibited at the National Archaeological Museum in Chiusi. (Marco Daniele / CC BY-SA 3.0)

glirarium exhibited at the National Archaeological Museum in Chiusi. (Marco Daniele / CC BY-SA 3.0)

The problem with this interpretation, however, is that the museum’s jar has neither the paths nor the food holders within it as described by Varro. It may be possible, though, that these features were made not with clay but with material that has since disintegrated. Incidentally, it is unclear if such paths were found within the glirarium displayed by the museum in Chiusi, as the interior of the jar is not visible in images of the artifact. Alternatively, it has been suggested that the jar was used to hold snakes, as these creatures were a popular religious symbol in the ancient world. In any case the exact function of this jar remains a mystery till this day.

Top image: The Holey Jar restored.  Source: Katie Urban / Museum of Ontario Archaeology

By Wu Mingren


Byron, J., 2011. Did this holey jar hold a tasty Roman snack?. [Online] Available at:

Jarus, O., 2011. Ancient Roman Jar Riddled with Mystery. [Online] Available at:

Kelly, D., 2018. Historical artifacts we still can't explain. [Online] Available at:

Marcus Terentius Varro, Res Rusticae [Online] [Belvoir, F. H. (trans.), 1912. Marcus Terentius Varro’s Res Rusticae] Available at:

Silver, C., 2017. The Dormouse-Fattening Jars of Ancient Rome. [Online] Available at:

The History Blog, 2011. Roman jar filled with holes perplexes experts. [Online] Available at:



Quizá no era para almacenar líquidos; y, si recibía líquidos, quizá era parte de un entretenimiento. Pero bien que pudo funcionar como regadera.

dhwty's picture


Wu Mingren (‘Dhwty’) has a Bachelor of Arts in Ancient History and Archaeology. Although his primary interest is in the ancient civilizations of the Near East, he is also interested in other geographical regions, as well as other time periods.... Read More

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