The materials used in historical masonry structures are bricks and local stone, mainly of two types: a siliceous sandstone, rather compact and yellow-redish in colour, and a very compact whitish, pale-yellow or grayish-yellow calcareous stone, known as 'tuff '(or 'tuff rock').
These materials are either used on their own or in combination with the other in variable percentages.
[Learn More](http://esg.pt/3dpast/platform)