"Looks Like" a Sunken City off Cuba's Coast

In 2000-2001 there was some discussion of some images retrieved by echo-sounding of the seabed off the coast of the Guanahacabibes Peninsula in Pinar del Río, a province of Cuba. The images resembled, some said, stone structures with certain geometric features that could lead to their interpretation as the ruins of ancient human constructions. 

 The feature was first identified in 2000 by a team led by marine engineer Paulina Zelitski and her husband Paul Weinzweig, owners of the Canadian company Advanced Digital Communications (ADC), which was conducting seafloor surveys in collaboration with the Cuban government. In 2001, the team conducted further exploration using sonar, detecting regular geometric formations covering an area of approximately 20 km² at depths ranging from 600 to 750 meters. An underwater remotely operated vehicle (ROV) equipped with video captured images of what appeared to be circular and pyramid-like structures, possibly made from massive granite blocks. Zelitski described the formations as "a truly marvelous structure that really does resemble a large urban centre. However, it would be totally irresponsible to say what it is until we have proof". The depth rather precludes them being anthropogenic. No further studies have confirmed the existence of the feature or expanded upon the original findings. 

Despite that a rambling You Tube video by Dan Richards seems to think they are traces of a lost ancient civilization that he somehow (how?) dates to 50kYBP.... “The Sunken City off Cuba’s Coast: Atlantis or Anomaly?”, the mystery remains unresolved."The Sunken City off Cuba's Coast: Atlantis or Anomaly?"The Cuban Underwater Structure