In this talk I will introduce nuclear lattice effective field theory (NLEFT) that utilizes high-fidelity two- and three-nucleon forces. I will then present recent results for tin isotopes ⁹⁹Sn to ¹⁰²Sn near the proton dripline, reproducing binding energies with ~1% accuracy for even-even systems for a given set of three-body forces. The results confirm the shell closure at N=50.