In the dynamical systems theory, "edge of chaos" is a metaphor describing the transition point between order and chaos. For example, in the context of the logistic map the edge of chaos corresponds to a = 5.569945.., with a the bifurcation parameter. But inside the large chaotic region there are a lot of islands of periodicity characterized by a period-doubling cascade to chaos. Do we have more edges of chaos? What happens for Tinkerbell map, where there is no obvious road from period-doubling bifurcation to chaos? Where is the edge of chaos?