  The duality map between gauge theories and strings suggests that when the
gauge theory is in the weak coupling regime the dual string tension effectively
tends to zero, $\alpha' \to \infty$. This observation of Sundborg and Witten
initiates a fresh interest to the old problem of tensionless limit of standard
string theory and to the description of its genuine symmetries. We approach
this problem formulating tensionless string theory by means of geometrical
concept of surface perimeter. The perimeter action uniquely leads to a
tensionless string theory.
