Great Dolmen of Zambujeiro
Nossa Senhora da Tourega e Nossa Senhora de Guadalupe, Portugal
The Great Dolmen of Zambujeiro (Anta Grande do Zambujeiro) is a megalithic monument located in Nossa Senhora da Tourega, near Valverde, in the municipality of Évora, considered one of the biggest such structures in Iberia.
Monument data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).