This official Mayfair promo expansion is included on a tile sheet titled: Limited Edition Promo Expansion Set #10, which can be found in issue #175 of GTM. Includes two River Hex tiles. SETUP: You may place either or both of the 3-hex tiles anywhere on your river boards as long as two of the three hexes line up with river hexes underneath. Treat these tile river features as you would any on the standard the board tiles [i](sic)[/i]. These tiles do not move during gameplay.