In 1903 Alexander Graham Bell developed a design principle to generate lightweight, mechanically robust lattice structures based on triangular cells; this has since found broad application in lightweight design. Over one hundred years later, the same principle is being used in the fabrication of nanolattice materials, namely lattice structures comprised of nanoscale constituents. Taking advantage of size-dependent properties typical of nanoparticles, nanowires, and thin films, nanolattices redefine the limits of the accessible material property space throughout different disciplines. We review the exceptional mechanical performance of nanolattices, including their ultra-high strength, damage tolerance, and stiffness, and examine their potential for multifunctional applications beyond mechanics. The efficient integration of architecture and size-affected properties is key to further develop nanolattices. The introduction of hierarchical architecture is an effective tool in enhancing mechanical properties, and the eventual goal of nanolattice design may be to replicate the intricate hierarchies and functionalities observed in biological materials. Additive manufacturing and self-assembly techniques enabled lattice design at the nanoscale, the scaling-up of nanolattice fabrication is currently the major challenge to their widespread use in technological applications.