An access hatch (10; 110) for an opening such as that of a sub-surface facility, the access hatch (10; 110) having a frame for fitting to the perimeter of the opening, a cover lid pivotally coupled to the frame, and grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) in pivotable relationship with the frame, wherein the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) form two separate sub assemblies (30a, 30b), each sub assembly (30a, 30b) including two collapsible grate segments (16a, 16b, 16c, 16d) pivotally connected together, such that the access hatch (10; 110) is manoeuvrable between: a first configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) extend across the opening and the cover lid is pivoted into a closed position in which it at least substantially covers the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) and denies access to the opening; a second configuration in which the cover lid is pivoted to uncover the grate segments (16a, 16b, 16c, 16d) to allow inspection of the facility; and a third configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) and cover lid are moved into substantially upright positions so as to form a barrier around the opening, wherein from the second configuration, a sub assembly (30a, 30b) of the two separate sub assemblies (30a, 30b) is individually movable into a substantially upright position such that one side of the opening can be accessed, wherein the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) are substantially parallel with each other when the access hatch is in the first and second configurations and pivotable from the frame in the third configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) define sides of the barrier, wherein the barrier includes a substantially upright gated portion for selectively opening and closing the barrier to allow and restrict access to the opening respectively, and wherein the gated portion is formed in one of the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d). a first configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) extend across the opening and the cover lid is pivoted into a closed position in which it at least substantially covers the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) and denies access to the opening; a second configuration in which the cover lid is pivoted to uncover the grate segments (16a, 16b, 16c, 16d) to allow inspection of the facility; and a third configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) and cover lid are moved into substantially upright positions so as to form a barrier around the opening, wherein from the second configuration, a sub assembly (30a, 30b) of the two separate sub assemblies (30a, 30b) is individually movable into a substantially upright position such that one side of the opening can be accessed, wherein the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) are substantially parallel with each other when the access hatch is in the first and second configurations and pivotable from the frame in the third configuration in which the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d) define sides of the barrier, wherein the barrier includes a substantially upright gated portion for selectively opening and closing the barrier to allow and restrict access to the opening respectively, and wherein the gated portion is formed in one of the grate segments (16a, 16b, 16c, 16d; 116a, 116b, 116c, 116d).