Abstract: An easily transportable tiered grandstand consisting of a collapsible fluid-tight casing erectable by filling with a fluid and/or solid substances, such as gas and/or water, the casing having a base portion adapted when the casing is erected, to rest on a substantially flat horizontal support surface such as the ground and having a top portion which in the erected position forms a plurality of tiers. Flexible elements are provided internally of the casing connecting the bottom and top portions of the casing and being under tension when the casing is erected. Seats and gangways may be mounted on the top portion.