A structure that is movable and dynamic after construction, which links two points separated by a natural or man-made obstacle, the structure allowing the permanent crossing of this obstacle, the structure including: - a deformable spanning part which extends between said two points, - a set of elongated elements (2, 3), having three openings (5A, 5A', 5B), a first opening (5A, 5A') at each end of the elements (2, 3) and a second intermediate opening disposed between the two first openings (5A, 5A') present at the ends of the elements (2, 3), said openings (5, 5A, 5A') receiving ball joints forming hinges, each element (2, 3) consisting of a first short portion between a first opening and the intermediate opening and of a second longer portion between the other first opening and the intermediate opening, the elements (2, 3) being disposed in pairs, movable in rotation, around a central hinge constituted by a ball joint in the intermediate openings of two elements (2, 3) characterized by - an assembly of several pairs of elements (2, 3) made by ball joints inserted into the openings (5A, 5A') disposed at the ends of each element (2, 3), the assembly of said elements (2, 3) being disposed along the spanning part, on one side or on both sides of the spanning part in a plane substantially perpendicular to the axis of said hinges and allowing a relative movement of the elements (2, 3) from a first position to a second position taking place in said plane perpendicular to the axis of the hinges, - said short portions of the elements (2, 3) being disposed on the upper portion of the pairs of elements (2, 3) disposed at the ends of the structure while said short portions of the elements (2, 3) are disposed on the lower portion of the pairs of elements (2, 3) disposed towards the center of the structure, and - drive means disposed at one end or at both ends of said structure for adjusting the spanning part lengthwise, said drive means being arranged so that, when the means are actuated, they drive the assembly of the pairs of elements (2, 3), so as to bulge the central portion of the spanning part when both ends of the structure are drawn lengthwise, the drive means being actuable after construction of the structure so as to make it movable and dynamic. - a deformable spanning part which extends between said two points, - a set of elongated elements (2, 3), having three openings (5A, 5A', 5B), a first opening (5A, 5A') at each end of the elements (2, 3) and a second intermediate opening disposed between the two first openings (5A, 5A') present at the ends of the elements (2, 3), said openings (5, 5A, 5A') receiving ball joints forming hinges, each element (2, 3) consisting of a first short portion between a first opening and the intermediate opening and of a second longer portion between the other first opening and the intermediate opening, the elements (2, 3) being disposed in pairs, movable in rotation, around a central hinge constituted by a ball joint in the intermediate openings of two elements (2, 3) characterized by - an assembly of several pairs of elements (2, 3) made by ball joints inserted into the openings (5A, 5A') disposed at the ends of each element (2, 3), the assembly of said elements (2, 3) being disposed along the spanning part, on one side or on both sides of the spanning part in a plane substantially perpendicular to the axis of said hinges and allowing a relative movement of the elements (2, 3) from a first position to a second position taking place in said plane perpendicular to the axis of the hinges, - said short portions of the elements (2, 3) being disposed on the upper portion of the pairs of elements (2, 3) disposed at the ends of the structure while said short portions of the elements (2, 3) are disposed on the lower portion of the pairs of elements (2, 3) disposed towards the center of the structure, and - drive means disposed at one end or at both ends of said structure for adjusting the spanning part lengthwise, said drive means being arranged so that, when the means are actuated, they drive the assembly of the pairs of elements (2, 3), so as to bulge the central portion of the spanning part when both ends of the structure are drawn lengthwise, the drive means being actuable after construction of the structure so as to make it movable and dynamic.