Tools dating back 40,000 years including double-edged flint knife found in ancient castle cave

Scientists say the lower levels of the 13th century castle in Olsztyn contain traces of human activity from 40,000 years ago. Jerzy Strzelecki

Over 200 Neanderthal tools have been discovered by archaeologists in caves beneath a medieval castle in Silesia.

Now a scenic ruin, the castle in Olsztyn near Częstochowa was one of the defensive fortresses known as Trail of the Eagles' Nests guarding Poland’s borders built along the Kraków-Częstochowa Upland in the 14th century. 

Among the 40,000 Neanderthal tools was this double-edged flint knife. Mikołaj Urbanowski

The discovery was made during excavation works on the castle whilst manually rinsing sand and soil from the cave floor.

Among the rare items discovered were flint knifes and arrow heads from a time when Neanderthals walked the Earth alongside Homo Sapiens, before disappearing completely.  

The castle was one of the defensive fortresses known as Trail of the Eagles' Nests guarding Poland’s borders built along the Kraków-Częstochowa Upland in the 14th century.DTG

Dr. Mikołaj Urbanowski from the Przyroda i Człowiek Foundation (Nature and Man) who oversees the excavations told PAP: “We found out that the cave didn’t serve only as the renaissance castle pantry. Earlier, Neanderthals used it as shelter.”

Archaeologists also came across a fragment of a giant pillar which supported the cave and the upper castle standing on it. 

Archaeologists also came across a fragment of a giant pillar which supported the cave and the upper castle standing on it.Mikołaj Urbanowski

Said Dr. Urbanowski: “It was connected to an over a meter thick wall closing the cave, with both structures reaching high up, in case of the pillar even several dozen meters.

“The cave buttresses’ builders were probably worried about the castle stability, due to the empty space below it.” 

Unlike modern humans, Neanderthals were stockier, with shorter legs and bigger bodies.Charles R. Knight

He added: "The builders of the buttresses in the cave were probably worried about the stability of the castle due to the empty space below it. Therefore, it was decided to strengthen the cavern vault and at the same time support the walls of the upper castle."

The technique and clay mortar used suggest the castle’s was built in the 13th century.

The discovery was made during excavation works on the castle whilst manually rinsing sand and soil from the cave floor.Mikołaj Urbanowski

Another of the cave’s uses was discovered last year. The scientists came across a 15th century metallurgical furnace, with several kilograms of post-production waste – the alloys indicating it was used to produce bronze.

Urbanowski said: "The location of the furnace, which generates huge amounts of heat and toxic fumes, in a cave is a phenomenon at least in the case of Poland. Perhaps someone wanted the oven to stay out of sight, if the production served illegal  purposes, e.g. counterfeiting of coins. But at this stage it is only speculation.”