Effective string solutions appear in various physical systems e.g. superconductors, quantum chromodynamics. These types of solutions also exist in supersymmetric gauge theories; in fact, a typical string configuration resembles both superconducting ANO vortex and QCD flux tube. Spectrum of excitations of the string is described by a certain sigma model with four supercharges. Surprisingly, for a limited class of N=2 four dimensional gauge theories those effective string sigma models can be promoted to bona fide superstring theory with ten dimensional target space. We shall discuss those models and further implications of our results.