Applications of Hamiltonian Cycle Problem The Hamiltonian Cycle Problem and Travelling Salesman Problem are among famous NP-complete problems and has been studied extensively.

I am looking for applications of the HamCycle and TSP.
What are some interesting real world problems where the HamCycle and TSP come up?
One application involves stripification of triangle meshes in computer graphics — a Hamiltonian path through the dual graph of the mesh (a graph with a vertex per triangle and an edge when two triangles share an edge) can be a helpful way to organize data and reduce communication costs.