The trul­li , lime­stone dwellings found in the south­ern region of Puglia, are remark­able exam­ples of dry­wall (mor­tar­less) con­struc­tion, a pre­his­toric build­ing tech­nique still in use in this region. The trul­li are made of rough­ly worked lime­stone boul­ders col­lect­ed from neigh­bour­ing fields. Char­ac­ter­is­ti­cal­ly, they fea­ture pyra­mi­dal, domed or con­i­cal roofs built up of cor­belled lime­stone slabs.