We demonstrate nanoscale architectures in real biominerals and their biomimetics. Mimicking biomineralization, that is, crystal design in association with organic molecules, has been demonstrated in recent years. Although the macroscopic morphologies in real biominerals and biomimetics have been extensively studied, the nanoscopic structures in terms of the crystal growth are still not fully understood. We show that both materials form oriented architectures of bridged nanocrystals with incorporated organic polymers. The growth of nanocrystals by association with polymers is a significant step for the understanding and developing of crystal growth. The strategy could be applied to various systems in nanoscale crystal growth leading to functional materials.