The Zelitsky-Weinzweig Cuban Underwater Formation

                Location (BBC)                         

The Zelitsky-Weinzweig Cuban underwater formation is a site discovered by a sonar survey in 2001 thought by pseudoarchaeologists to be a submerged structural complex off the coast of the Guanahacabibes Peninsula in the Pinar del Río Province of Cuba (BBC, ' 'Lost city' found beneath Cuban waters' BBC, 7 December, 2001).

A team of explorers working off the western coast of Cuba say they have discovered what they think are the ruins of a submerged city built thousands of years ago. Researchers from a Canadian company used sophisticated sonar equipment to find and film stone structures more than 2,000 feet (650 metres) below the sea's surface. [...] Advanced Digital Communications is one of four firms working in a joint venture with President Fidel Castro's government to explore Cuban waters, which hold hundreds of treasure-laden ships from the Spanish colonial era. The explorers first spotted the underwater city last year, when scanning equipment started to produce images of symmetrically organized stone structures reminiscent of an urban development. [...] "It's a really wonderful structure which really looks like it could have been a large urban centre," ADC explorer Paulina Zelitsky told the Reuters news agency.

A computer-generated image based on the sonar imaging of the underground structures off the coast of Cuba (photo credit: courtesy of ADC cor)

Sonar images interpreted as being symmetrical and geometric stone structures resembling an urban complex were recorded covering an area of 2 square kilometres (200 ha) at depths of between 600 metres (2,000 ft) and 750 metres (2,460 ft). The discovery was reported by Paulina Zelitsky, a marine engineer, and her husband Paul Weinzweig, owners of a Canadian company called Advanced Digital Communications. The team returned to the site a second time with an underwater remotely operated vehicle that filmed sonar images interpreted as various pyramids and circular structures. The discoverers for some reason claim that these were "made out of massive, smooth blocks of stone that resembled hewn granite". 

The depth is unusual, it has been stated that these structures could have been at sea level 50,000 years ago. 
 

Although the initial discovery was widely reported in the press and briefly discussed in outlets like BBC News and National Geographic, with speculation about its age and potential significance, there has been no major documented scientific expedition or systematic underwater excavation after the early 2000s. No detailed results or reports were ever published in academic journals, and it appears that any further more detailed work took place or yielded no further publicly available findings. There is no peer-reviewed archaeological publication confirming the site as a human-made structure, the sonar findings and ROV footage from ADC have not appeared in mainstream archaeological or geological journals as formal, peer-reviewed research. There are no confirmed radiometric dates, stratigraphic profiles, tool marks, or recovered artefacts published that would support an anthropogenic interpretation at this site. As a result, The expert consensus — as reflected by geologists, oceanographers, and archaeologists — remains sceptical or cautious.Morphology and symmetry alone are insufficient to infer human construction; many geological processes can produce regular shapes at the seafloor. The site still exists physically: The underwater topography seen in sonar remains part of the seafloor off Guanahacabibes, and is available for re-surveyy at any time (given the agreement of Cuban authorities). The question is why nobody interested in "alternative pasts" has taken a serious interest in organizing such an expedition. As Keith Fitzpatrick- Matthews puts it:

" The story was given a new lease of life thanks to its exposure in Ancient Aliens, but no new information about it has emerged. After the initial flurry of excitement, once scientists began to look critically at the data, especially the sonar images, the story could be seen to be nothing more than hype. For anyone outside the small band of “alternative researchers” and New Age true believers, the story simply died for lack of evidence. But when did a lack of evidence ever stop woo-woos making unsupported claims?"

See also:

'Zelitski, Paulina' in Atlantipedia  June 13, 2010. 

Linda Moulton Howe, 'Update on Underwater Megalithic Structures near Western Cuba', Wayback Machine November 19, 2001.

Keith Fitzpatrick-Matthews, 'An underwater city west of Cuba', Bad Archaeology 28 October 2012.