  Anderson proposed structural topology in frustrated magnets hosting novel
quantum spin liquids (QSLs). The QSL state is indeed exactly derived by
fractionalizing the spin excitation into spinless Majorana fermions in a
perfect two dimensional (2D) honeycomb lattice, the so-called Kitaev lattice,
and its experimental realisation is eagerly being pursued. Here we, for the
first time, report the Kitaev lattice stacking with van der Waals (vdW) bonding
in a high quality {\alpha}-RuCl$_3$ crystal using x-ray and neutron
diffractions. Even in absence of apparent monoclinic distortion, the system
exhibits antiferromagnetic (AFM) ordering below 6.5 K, likely due to minute
magnetic interaction from trigonal distortion and/or interlayer coupling
additionally to the Kitaev Hamiltonian. We also demonstrate 2D Ising-like
critical behaviors near the N\'eel temperature in the order parameter and
specific heat, capturing the characteristics of short-range spin-spin
correlations underlying the Kitaev model. Our findings hold promise for
unveiling enigmatic physics emerging from the Kitaev QSL.
