Abstract: A tent-like structure, hereafter called a pavilion with a series of curved arches and a panel of flexible membranous material attached to each pair of arches and tensioned in both directions with the panels concavely curved in the direction of the spacing of the arches as well as convexly curved in the other direction to minimize flutter and vibration and to enhance its load-carrying capacity. The panels are attached to the arches by inserting beads on their edges into tunnels in the arches so that the panels may slide lengthwise of the arches to tension them lengthwise. The arches are mounted on rails to swing from recumbent to upright positions and to slide toward each other, to to facilitate assembly of (attach) the panels to the arches, and away from each other, to tension the panels transversely. To move the arches apart and tension the panels transversely, extensible struts, such as toggles or jack-screws, are provided between (each pair of) the arches.