The set of Penrose tilings, when provided with a natural compact metri
c topology, becomes a strictly ergodic dynamical system under the acti
on of R(2) by translation. We show that this action is an almost 1:1 e
xtension of a minimal R(2) action by rotations on T-4, i.e., it is an
R(2) generalization of a Sturmian dynamical system. We also show that
the inflation mapping is an almost 1:1 extension of a hyperbolic autom
orphism on T-4. The local topological structure of the set of Penrose
tilings is described, and some generalizations are discussed.