Super-resolution microscopy has revolutionized the fields of chemistry and biology by resolving features at the single molecule level. In cold atoms, such a scheme can be furthered to reveal the atomic wavefunction of typically 100 nm in size. Here we report super-resolution imaging based on optical pumping, reaching a half-width-at-half-maximum resolution of 16(2) nm. The center of mass position can be determined with a precision below 500 pm. Our imaging process lasts for only 1 micro-second, which enables us to resolve fast dynamics of atoms within a single lattice site. A surprising observation is the emergence of moiré patterns on the atomic cloud, which can immensely magnify atomic density profile from nano-meter scale to milli-meter scale.