 Chinese imperial tombs are typically approached by a "spirit road", sometimes several kilometres long, lined by statues of guardian figures, based on both humans and animals.A tablet extolling the virtues of the deceased, mounted on a stone representation of Bixi in the form of a tortoise, is often the centerpiece of the ensemble.In Han tombs the guardian figures are mainly of "lions" and "chimeras"; in later periods they are much more varied.