Sweden's Earliest Onion

The onion looked almost like a nut.
 Photo: Jens Heimdahl/Swedish History Museum
(found in Archaeology Magazine's website) 

A relatively recent archaeological find of an Iron Age ringfort at Sandby Borg on the island of Öland in Sweden documents a massacre that happened in the 5th century CE. The excavations at the fort show that people were killed but never buried; their remains are preserved where they fell. Because of that fact, the find also shows us a lot about everyday life in 5th century Sweden, including what may be one of the first onions found in that country.  The next oldest archaeological find of an onion in Sweden is dated to approximately 650 CE.

The onion in question was found near a fireplace in one of the structures within the bounds of the fort. It was originally thought to be some kind of nut, but laboratory analysis confirmed that it was an onion that had been burnt.  

Archaeology magazine features a short article with a photograph of the historical onion, but other articles give more context here, here, and here.  It is currently believed that the onion was imported to Sweden by the Romans, who already used onions regularly in their diet.