Mysterious Ancient Megastructure Discovered Lurking Beneath The Baltic Sea

<img width="128" height="52" src="https://www.sciencealert.com/images/2024/02/blinkerwall-header-alt.jpg" alt="Undersea morphology of the region, collected using a remote vehicle. White arrows point to the Blinkerwall."/>
It seems to have been deliberately constructed?

https://www.sciencealert.com/mysterious-ancient-megastructure-discovered-lurking-beneath-the-baltic-sea