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Abstract. A complete simply connected Riemannian manifold H without conjugate points satisfies the uniform Visibility axiom if the angle subtended at a point p by any geodesic y of H tends uniformly to zero as the distance from p to y tends uniformly to infinity. A complete manifold Mis a uniform Visibility manifold if it has no conjugate points and if the simply connected covering H satisfies the uniform Visibility axiom. We derive criteria for the existence of uniform Visibility manifolds. Let M be a uniform Visibility manifold, SM the unit tangent bundle of M and Tt the geodesic flow on SM. We prove that if every point of SM is nonwandering with respect to Tt then Tt is topologically transitive on SM. We also prove that if M' is a normal covering of Mthen Tt is topologically transitive on SM' if Tt is topologically transitive on SM.