An anchor for anchoring an underground storage tank, the anchor comprising: a composite base comprising: a footing ; and a spine extending upwardly from the footing so as to define footing portions on either side of the spine ; wherein the footing and the spine have a composite composition comprising: a matrix material; and a reinforcement structure embedded within the matrix material; and a retention mechanism connected to the spine of the composite base for retaining a hook for anchoring the underground storage tank, wherein the retention mechanism comprises. an opening in the spine; characterised in that the retention mechanism further comprises J a first chamber and a second chamber extending from the opening in generally opposed relation to each other in the spine ; a retention member comprising a first end and a second end respectively insertable into the first chamber and the second chamber , the retention member being sized and configured to be displaceable between: an open position where the first end of the retention member is located within the opening and is insertable through the hook; and a closed position where the first end is located within the first chamber and the second end is located in the second chamber , thereby retaining the hook with respect to the retention member . a composite base comprising: a footing ; and a spine extending upwardly from the footing so as to define footing portions on either side of the spine ; wherein the footing and the spine have a composite composition comprising: a matrix material; and a reinforcement structure embedded within the matrix material; and a footing ; and a spine extending upwardly from the footing so as to define footing portions on either side of the spine ; wherein the footing and the spine have a composite composition comprising: a matrix material; and a reinforcement structure embedded within the matrix material; and a matrix material; and a reinforcement structure embedded within the matrix material; and a retention mechanism connected to the spine of the composite base for retaining a hook for anchoring the underground storage tank, wherein the retention mechanism comprises. an opening in the spine; characterised in that the retention mechanism further comprises J a first chamber and a second chamber extending from the opening in generally opposed relation to each other in the spine ; a retention member comprising a first end and a second end respectively insertable into the first chamber and the second chamber , the retention member being sized and configured to be displaceable between: an open position where the first end of the retention member is located within the opening and is insertable through the hook; and a closed position where the first end is located within the first chamber and the second end is located in the second chamber , thereby retaining the hook with respect to the retention member . an open position where the first end of the retention member is located within the opening and is insertable through the hook; and a closed position where the first end is located within the first chamber and the second end is located in the second chamber , thereby retaining the hook with respect to the retention member . <EOS>