Artificial caves of Alapraia - Credit: Wikimedia Commons
Artificial caves of Alapraia - Credit: Wikimedia Commons
The Artificial caves of Alapraia () constitute a prehistoric necropolis formed by four subterranean tombs or hypogea that were created by excavating marlstone rock using stone tools. They are situated in the centre of the suburb of Alapraia in Estoril, Lisbon District, Portugal and are believed to date back to the last quarter of the 4th Millennium BCE and to have been used as a necropolis for over one thousand years. Read more on Wikipedia
Source: en.wikipedia.org