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.