Intractable computations without local minima

An NP-complete problem which is not a spin-glass is exhibited. The NP-complete problem 3-satisfiability is also embedded into a continuous analog system with no hills in the energy landscape obstructing solution of the problem. There is, however, a large flat plateau. This shows how sculpting of the energy surfaces of continuous analog systems to remove hills may fail to aid solution of embedded combinatorial optimization problems.