  The quantum anomalous Hall effect (QAHE) is a robust topological phenomenon
featuring quantized Hall resistance at zero magnetic field. We report the QAHE
in a rhombohedral pentalayer graphene/monolayer WS2 heterostructure. Distinct
from other experimentally confirmed QAHE systems, this system has neither
magnetic element nor moir\'e superlattice effect. The QAH states emerge at
charge neutrality and feature Chern numbers C = +-5 at temperatures up to about
1.5 K. This large QAHE arises from the synergy of the electron correlation in
intrinsic flat bands of pentalayer graphene, the gate-tuning effect, and the
proximity-induced Ising spin-orbit-coupling. Our experiment demonstrates the
potential of crystalline two-dimensional materials for intertwined electron
correlation and band topology physics, and may enable a route for engineering
chiral Majorana edge states.
