A large aluminum object dating back 250,000 years is controversial because it appeared much earlier than the time people knew about aluminum metal.

The strange aluminum object has recently caused a lot of controversy because experts assess it to be at least 250,000 years old, while humanity has only been able to produce metallic aluminum about 200 years ago, according to Mirror.

In 1973, a group of construction workers working on the banks of the Mures River near the Romanian town of Aiud found three objects 10 meters below ground. Because the objects dug up seemed unusual and old, archaeologists were invited to the site. They immediately recognized two of the three objects as animal bone fossils.

The remaining object was very light, looked like a human-made metal object, and was shaped like an ax blade. All three items were sent to the city of Cluj in the province of Transylvania, Romania for further analysis. Experts quickly discovered that two large bones belonged to a mammal that died 10,000 – 80,000 years ago. However, the third object surprised them greatly.

According to test results, the object is made of 12 metals with 90% aluminum, dating back 250,000 years. This assessment result was later confirmed by a laboratory in Lausanne, Sweden. Some other experts give different dates for the object, from 400 to 80,000 years. Even though it is at least 400 years old, the object was still 200 years earlier than when humans first learned about the material aluminum.

The object is 20 cm long, 12.5 cm wide and 7 cm thick. What confuses experts is that the metal block has a concave surface that looks like a part of a complex mechanical system.

Many unidentified flying object (UFO) hunters believe that this object is a fragment of a flying saucer, evidence that alien civilizations have visited Earth in the past.

Romanian historian Mihai Wittenberger believes that the piece of aluminum is part of a German World War II plane, but cannot explain the age of the object. The object is being exhibited at the Cluj-Napoca Historical Museum with the note “origin unknown”.