Answer:
The absence of agricultural activity.
Step-by-step explanation:
Lepenski Vir is an archaeological site located in Serbia. This site was most likely occupied since 9500-7200 BCE. Because of this, and the level of sophistication of the inhabitants, it has been called the "first city in Europe." The site is notable for the level of preservation and the quality of the artifacts that were found here. However, it seems like for a period of time, this site was used temporarily, as there is no evidence of agricultural activity.