Portugal, in the 12th century, began as a county, that is, governed by a count. Wikipedia notes that it “refers to two successive medieval counties in the region around Braga and Porto, today corresponding to littoral northern Portugal, within which the identity of the Portuguese people formed. The first county existed from the mid-ninth to the mid-eleventh centuries as a vassalage of the Kingdom of Asturias and later the Kingdoms of Galicia and León, before being abolished as a result of rebellion. A larger entity under the same name was then re-established in the late 11th century and subsequently elevated by its count in the mid-12th century into an independent Kingdom of Portugal.”
Impressive megalithic sites are to be found in Portugal, among which is the large Almendres Cromlech (Cromeleque dos Almendres) near Evora. It still has 93 huge stones that form two concentric rings. They were erected there around 4000-5000 BC making them about 2000 years older than Stonehenge(a).
>A recent article(e) on Graham Hancock’s website by Leonard Wolf describes a number of megalithic sites in Portugal that he personally explored including some in the Evora district in 2022. In 2015, the same Mr. Wolf published a lengthy paper(f) advocating a site off the coast of Mexico’s Yucatan Peninsula as the location of Atlantis.<
According to Mel Nicholls , the Bell Beaker culture originated in Portugal around 2800 BC and has nominated the Beaker people in Britain as Atlantean, whereas Donald Ingram argues that their successors in Britain, the Wessex II culture were Atlantean.
Portugal entered the Atlantis Stakes with a claim by a Basque researcher, Luis Aldamiz, that a little-known ancient civilisation, known as the Villa Nova de São Pedro (VNSP) culture matched much of Plato’s description of Atlantis(b). Its capital was Zambujal, which was located on a mountain in the centre of the Estramadura peninsula, near modern Lisbon. Originally it was described as a ‘perriruthos’, which indicates something surrounded by water. Aldamiz notes that ten tombs were found there; reminiscent of the ten kings of Atlantis. Zambujal had large complex fortifications. Aldamiz claims that this civilisation fought against the Greeks during the Middle Bronze Age. He further believes that the destruction of his Atlantis was caused by an event that was similar to the 1755 Lisbon earthquake that caused such death and destruction.
Lereno Barradas was a Portuguese writer who speculated in the early 1970s that Tartessos could be identified with Atlantis and that it had been located in the Tagus estuary near the site of modern Lisbon. He also suggested that these ancient Atlanteans had travelled to America.
In 1989 another Portuguese researcher, José Antunes, proposed that Atlantis had been situated in what is now northwest of Lisbon between Sintra and Mafra.
A more radical theory has been put forward by Roger Coghill, the British bioelectromagnetic investigator, who suggests on his website that Atlantis was located in the vicinity of Faro in the Algarve. Coghill expanded on his theory in his book, The Message of Atlantis. He has also drawn attention to a book  by Antonio Jose Lopes Navarro, published in 1983, in which he has brought together a number of classical references to the prehistory of the Algarve.
Portugal got further attention in 2013 when another British researcher, Peter Daughtrey, who then lived in Portugal, published Atlantis and the Silver City  in which he designates not just the Algarve and the submerged area in front of it as Atlantis, but the whole of that south-west Iberian region.
Daughtrey’s book has been updated and contains what he calls “dramatic new evidence”. His book is supported by a website(d), where you will find additional articles, interviews and reviews.
The late Steven Sora suggested  that the Etruscans were refugees from their original homeland in Iberia, where he also located Troy/Atlantis. He specified Lisbon, Setubal and Troia, all in modern Portugal, as Trojan/Atlantean territory, conflating the Trojan and Atlantean wars, although placing those conflicts 4,000 km away from the battleground at Hissarlik, where Eberhard Zangger claims his Troy, which he also deemed to be identical with Atlantis was located!
Apart from the mainland claims the Portuguese Atlantic archipelagos of Azores and Madeiras have also been identified by several commentators as probable Atlantis locations.
Manuel J.Gandra has produced a valuable bibliography(c) of Portuguese sources dealing with Atlantis.
(c) Wayback Machine (archive.org)
(e) https://grahamhancock.com/wolfl3/ *
Mexico, according to the most recent evidence has pushed back the arrival date of the first people to the southern regions of the country to around 30,000 BC(e).
Mexico has not been ignored by Atlantis seekers. As early as the 17th century Carlos de Sigüenza y Góngora suggested that the indigenous people of Mexico had come from Atlantis after an earlier migration from Egypt. Louis de Launay, the French geologist, proposed in 1936, the possibility of such a link possible in 1936. More recently Gene Matlock has promoted the idea again with his own twist to the theory involving a link with ancient India. His ideas are available online(d).
An interesting attempt at linking Plato’s Atlantis story with the Valley of Mexico can be found on the Internet(a) in an article by Ed Ziomek that looks at possible links between the Old World and the Americas 5,000 years before Columbus.
In Frank Joseph’s Discovering the Mysteries of Ancient America [934.217] a chapter by Kenneth Caroli has offered evidence that Olmec Mexico was the Land of Punt in Egyptian legend.
Dustin Kolb is a German researcher who has opted for a Mexican location for Atlantis(h). Somehow or other he arrived at the conclusion that Plato’s description of Atlantis could only have been a reference to America. He then ‘reasoned’ that since the capital of Atlantis was in the middle of Plato’s island, this must have been a reference to Central America! Moving steadily along, he next decided that the concentric rings of the Atlantean capital could only have been an impact crater. He finally settled on the region of Lake Texcoco in the Valley of Mexico as the original home of Atlantis.
Clyde Winters has published his views that the Olmecs were descendants of Atlanteans who came from Libya in North Africa. However, another Afrocentrist Paul Barton claims(c) that the Olmecs came from the Mende people of West Africa who are now one of the principal ethnic groups of Sierra Leone.
Philip Gardiner has written a short article(g) in which he suggests America held the land of Atlantis, being the only large landmass beyond Gibraltar, where he believes Plato’s ‘Pillars of Heracles’ were located. Based on several factors including linguistics, he favours Mexico as the location of Plato’s lost land!(f)
A Mexican engineer, Eduardo Robles y Gutierrez, while working in Vera Cruz, discovered the foundations of an ancient city about 30 miles from the coast, in and near what is now the jungle-covered region of San Lorenzo Tenochtitlán. He has identified that ancient city, with its concentric channels lined with high banks, as had Plato’s Atlantis. The site had been pillaged by the Spanish who consigned considerable treasure back to Spain. His investigations were also published in Mexico as La Atlántida Está en México .
The fact that many Mexican placenames begin with ‘atl’ has prompted a number of commentators to erroneously assume a connection with ‘atl’antis.
A Mexican website(b) informs us that there is a village called ‘Atlantis’ in the Municipality of Cacahoatán (State of Chiapas). It has 8 people and is at a height of 550 meters.
>In 2015, Leonard Wolf published a lengthy paper(i) on the Graham Hancock website in which he endeavours to demonstrate that off the northern coast of Mexico’s Yucatan Peninsula lie the remains of Atlantis. He uses a mixture of Google Earth imagery, an unidentified coin linked to Stonehenge, Tarot cards and much more all bound together with unbridled speculation.<
(a) https://www.world.mysteries.com/gw_edziom2.htm (offline) see https://www.eupedia.com/forum/archive/index.php/t-9206.html
(b) Mexico.pueblosamerica.com/i/la-Atlantean/ (offline)
(e) New clues suggest people reached the Americas around 30,000 years ago | Science News
(g) See: Archive 2920
(h) Atlantis was in Mexico – Atlantisforschung.de (atlantisforschung-de.translate.goog)