In this review we report the most recent applications of nanotechnology to the conservation and restoration of the world’s cultural heritage. Nanoparticles of humble calcium and magnesium hydroxide and carbonate can be used to restore and protect wall paints and to de-acidify paper and wood. We highlight the synthetic pathways that can be used to produce nanoparticles, and some applications for the conservation of Maya wall paints in Mexico and to the de-acidification of paper documents and wood.