A building closure (1, 1', 1") of blast-resistant design, comprising - an outer frame, which can be connected in a force-transmitting manner to a part of a building by means of at least one fastening element and is composed of a plurality of outer frame members (6, 8) in the form of profiled pieces, - a leaf frame, which is mounted in the outer frame such that said leaf frame can rotate about at least one rotation axis (3, 3') with the aid of at least one fitting element and is composed of a plurality of leaf frame members (7, 9) in the form of profiled pieces, - a panel, which is fastened in the leaf frame, - a retaining device (14, 14', 14") in the form of at least one flexible pulling means (15, 15', 15"), which couples the leaf frame to the outer frame or to a fastening element of the outer frame, is connected in a force-transmitting manner to the leaf frame and to the outer frame or to the fastening element of the outer frame, and has such a length that the leaf frame can be moved from a closed position to an open position by rotation about the rotation axis (3, 3'), it being possible, if the leaf frame is torn out of the outer frame by a blast, for the leaf frame to be held in a caught position at a defined distance from the outer frame by means of the pulling means (15, 15', 15"), which then transmits a holding force, the pulling means (15, 15', 15") being arranged in a rebate region between the leaf frame and the outer frame such that said pulling means is invisible from outside the building closure (1, 1', 1") when the leaf frame is in the closed position, characterised in that the pulling means (15, 15', 15"), at least in one section, is composed of at least two individual cables (22, 22', 22"), which run adjacently to each other and can be bent independently of each other along a longitudinal axis of the respective cable (22, 22', 22"). - an outer frame, which can be connected in a force-transmitting manner to a part of a building by means of at least one fastening element and is composed of a plurality of outer frame members (6, 8) in the form of profiled pieces, - a leaf frame, which is mounted in the outer frame such that said leaf frame can rotate about at least one rotation axis (3, 3') with the aid of at least one fitting element and is composed of a plurality of leaf frame members (7, 9) in the form of profiled pieces, - a panel, which is fastened in the leaf frame, - a retaining device (14, 14', 14") in the form of at least one flexible pulling means (15, 15', 15"), which couples the leaf frame to the outer frame or to a fastening element of the outer frame, is connected in a force-transmitting manner to the leaf frame and to the outer frame or to the fastening element of the outer frame, and has such a length that the leaf frame can be moved from a closed position to an open position by rotation about the rotation axis (3, 3'), it being possible, if the leaf frame is torn out of the outer frame by a blast, for the leaf frame to be held in a caught position at a defined distance from the outer frame by means of the pulling means (15, 15', 15"), which then transmits a holding force, the pulling means (15, 15', 15") being arranged in a rebate region between the leaf frame and the outer frame such that said pulling means is invisible from outside the building closure (1, 1', 1") when the leaf frame is in the closed position,