Abstract: A domed structure having a retractable roof comprises a field area obtained by digging out a hollow, substantially concave in section, in the ground and levelling the bottom of the hollow seats for the spectators are provided by extending an upward slope outwardly from the end of the field area in an endless manner, and a movable roof element is movably mounted on a rail element laid out on the ground adjacent to the peripheral edge of said hollow. The movable roof element includes a driving arrangement to be placed on the rail element. The rail element may be tilted with a gradient rising toward the direction of solar radiation.

Abstract: A domed structure having a retractable roof comprises an inside field area, a ringed structure vertically provided around said field area, two tracks laid out on the top of said ringed structure and two movable semi-vaults travelling separately on said two annular tracks, which are put one over the other when the roof is opened and are located in opposite relation to each other when the roof is formed, thereby providing a domed roof as a whole. The annular tracks laid out on the top of said ringed structure may have a gradient rising with respect to the direction of solar radiation.