s 10 Review of maps (Wales) .
(1) Where the appropriate countryside body have issued a map in conclusive form in respect of any area in Wales , it shall be the duty of the body from time to time, on a review under this section, to consider— (a) whether any land shown on that map as open country or registered common land is open country or registered common land at the time of the review, and (b) whether any land in that area which is not so shown ought to be so shown. (2) A review under this section must be undertaken— (a) in the case of the first review, not more than ten years after the issue of the map in conclusive form, and (b) in the case of subsequent reviews, not more than twenty years after the previous review. (3) Regulations may amend paragraphs (a) and (b) of subsection (2) by substituting for the period for the time being specified in either of those paragraphs such other period as may be specified in the regulations.