Mainland Portugal is divided in 18 districts, each district is divided in multiple municipalities (Municípios) and each municipality is divided in multiple civil parishes (Freguesias).
The islands of Azores and Madeira, and most of Portuguese Mainland coastal parishes are excluded from the low density areas (with some exceptions in the districts of Setúbal, Beja and Faro). By contrast all the interior districts are low density areas (with the exception of some Municipalities of the district of Santarém and some parishes of the district of Viseu).
For your convenience you can find bellow (organised by district) which municipalities (or what parishes within a municipality) are considered as a low density area for Golden Visa purposes as of 2020.
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
No municipality in this district is considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district have at least one parish considered as low density area for Golden Visa Purposes
All municipalities in this district are considered as low density area for Golden Visa Purposes
All municipalities in this district (with exception of some parishes in the Municipality of Viseu) are considered as low density area for Golden Visa Purposes