Significance A long-standing challenge in modern materials manufacturing and design has been to create porous materials that are simultaneously lightweight, strong, stiff, and flaw-tolerant. Here, we fabricated pyrolytic carbon nanolattices with designable topologies by a two-step procedure: direct laser writing and pyrolysis at high temperature. The smallest characteristic size of the nanolattices approached the resolution limits of the available 3D lithography technologies. Due to the designable unit-cell geometries, reduced feature sizes, and high quality of pyrolytic carbon, the created nanoarchitected carbon structures are lightweight, can be made virtually insensitive to fabrication-induced defects, attain nearly theoretical strength of the constituent material, and achieve specific strength up to one to three orders of magnitude above that of all existing micro/nanoarchitected materials.