Grutas Artificiais de Alapraia | |
 | |
| Location | Estoril, Lisbon District, Portugal |
|---|---|
| Coordinates | 38°42′23″N 9°22′38″W / 38.70639°N 9.37722°W |
| Type | Necropolis |
| History | |
| Periods | Prehistoric, Chalcolithic, Bronze Age, |
| Site notes | |
| Discovered | 1889 |
| Excavation dates | 1889; 1932; 1942-43 |
| Archaeologists | F. de Paula e Oliveira, 1889; Father Eugénio Jalhay and Lieutenant Colonel Afonso do Paço, 1932 and 1942-43 |
| Public access | Outside only |
The Artificial caves of Alapraia (Portuguese: Grutas Artificiais de 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.