  We introduce the concept of "absolutely classical" spin states, in analogy to
absolutely separable states of bi-partite quantum systems. Absolutely classical
states are states that remain classical under any unitary transformation
applied to them. We investigate the maximum ball of absolutely classical states
centered on the fully mixed state that can be inscribed into the set of
classical states, and derive a lower bound for its radius as function of the
total spin quantum number. The result is compared to the case of absolutely
separable states.
