Ferro-rotational (ferroaxial) materials, characterized by spontaneous rotational distortion of structural units, exhibit compelling magnetoelectric properties for energy-efficient data storage and microelectronic applications. However, nanoscale visualization and crystallographic characterization of ferro-rotational domains remain largely unexplored and present significant challenges. Here, we report the direct observation of nanoscale ferro-rotational domain structures in RbFe(MoO4)2 using cryogenic transmission electron microscopy (TEM). We find that the ferro-rotational domain walls preferentially orient perpendicular to the ferro-rotational moment along the crystallographic {001} planes, forming head-to-head or tail-to-tail configurations that assemble three-dimensionally into stacked, plate-like domain structures. Using atomic-resolution four-dimensional scanning TEM (4D-STEM) and density functional theory calculations, we reveal that the {001} domain walls are energetically favored and atomically sharp (~ 1.5 nm wall width). This preference originates from bonding anisotropy relative to the rotational axis, suggesting that such domain-wall orientation may be universal among displacive-type ferro-rotational systems. The reported plate-like domains are expected to host charged ferroelectric domain walls below the Néel temperature (TN ≈ 4 K), providing a platform for exploring magnetoelectric phenomena localized at the domain walls.