Molecular dynamics simulations of bent [100] -Fe nanowires show the nucleation of twins and nanoscale interfaces that lead to pseudo-elasticity during loading/unloading cycles. The new type of interfaces along {110} stems from the accumulation of individual < 111 >/{112} twin boundaries and stores high interfacial energies. These nonconventional interfaces provide a large part of the driving force for shape recovery upon unloading, while the minimization of surface energy is no longer the dominant driving force. This new pseudo-elastic effect is not much affected by surface roughness, and can be extended over a wide range of wire diameters, if the sample is seeded with conventional twin boundaries, which will transform to the desired {110} interfaces under bending.