Celtic Julia Garden

The Celtic variant z -> |Re(z^2)| + i Im(z^2) + c iterated in the dynamical plane at fixed c = -1.35, taken from the real period-doubling cascade inside the connectedness locus. Real c adds a mirror in the real axis to the twofold rotation every Celtic Julia set carries, so the plan is a fourfold parterre. Luminance is a distance estimate from the exact real 2 by 2 Jacobian, log-scaled in both directions, and the gold is laid on by distance to the wall rather than by depth.