Wall found at bottom of Baltic Sea 'may be Europe’s oldest megastructure'

The linked article is about the discovery of an ancient stone age wall found beneath the waves off Germany’s Baltic coast that may be the oldest known megastructure built by humans in Europe. The submerged wall stretches for nearly a kilometre along the seafloor and consists of nearly 300 larger boulders connected by 1,400 smaller stones thought to weigh more than 142 tonnes. The wall may have been constructed by hunter-gatherers more than 10,000 years ago and was probably used as an ancient hunting lane before being submerged with rising sea levels about 8,500 years ago.