Structural DNA nanotechnology is revolutionizing the ways researchers construct arbitrary shapes and patterns in two and three dimensions on the nanoscale. Through Watson-Crick base pairing, DNA can be programmed to form nanostructures with high predictability, addressability, and yield. The ease with which structures can be designed and created has generated great interest for using DNA for a variety of metrology applications, such as in scanning probe microscopy and super-resolution imaging. An additional advantage of the programmable nature of DNA is that mechanisms for nanoscale metrology of the structures can be integrated within the DNA objects by design. This programmable structure-property relationship provides a powerful tool for developing nanoscale materials and smart rulers.