  An integrable anisotropic Heisenberg spin chain with nearest-neighbour
couplings, next-nearest-neighbour couplings and scalar chirality terms is
constructed. After proving the integrability, we obtain the exact solution of
the system. The ground state and the elementary excitations are also studied.
It is shown that the spinon excitation of the present model possesses a novel
triple arched structure. The elementary excitation is gapless if the
anisotropic parameter $\eta$ is real while the elementary excitation has an
enhanced gap by the next-nearest-neighbour and chiral three-spin interactions
if the anisotropic parameter $\eta$ is imaginary. The method of this paper
provides a general way to construct new integrable models with
next-nearest-neighbour interactions.
