A face seal assembly for a gas turbine engine, comprising: a seal ; and a seal carrier , the seal carrier including: a main plate portion ; a cylindrical body extending away from the main plate portion ; and a seal retention structure at an end of the cylindrical body distal from the main plate portion , the seal retention structure including: a first seal wall , a second seal wall and a base seal wall , the first seal wall , the second seal wall and the base seal wall defining a groove for receiving the seal therein, the second seal wall extending radially outwardly to a non-uniform radial location; wherein the main plate portion defines anti-rotation slots and provides flanges for attachment of spring fastener features ; characterised in that the second seal wall includes a plurality of segments extending to a common, first radial location and a plurality of recessed portions extending to a second radial location that is radially inward of the first radial location; and each of the plurality of recessed portions extends circumferentially between an adjacent pair of the plurality of segments . a seal ; and a seal carrier , the seal carrier including: a main plate portion ; a cylindrical body extending away from the main plate portion ; and a seal retention structure at an end of the cylindrical body distal from the main plate portion , the seal retention structure including: a first seal wall , a second seal wall and a base seal wall , the first seal wall , the second seal wall and the base seal wall defining a groove for receiving the seal therein, the second seal wall extending radially outwardly to a non-uniform radial location; wherein the main plate portion defines anti-rotation slots and provides flanges for attachment of spring fastener features ; characterised in that the second seal wall includes a plurality of segments extending to a common, first radial location and a plurality of recessed portions extending to a second radial location that is radially inward of the first radial location; and each of the plurality of recessed portions extends circumferentially between an adjacent pair of the plurality of segments . a main plate portion ; a cylindrical body extending away from the main plate portion ; and a seal retention structure at an end of the cylindrical body distal from the main plate portion , the seal retention structure including: a first seal wall , a second seal wall and a base seal wall , the first seal wall , the second seal wall and the base seal wall defining a groove for receiving the seal therein, the second seal wall extending radially outwardly to a non-uniform radial location; wherein the main plate portion defines anti-rotation slots and provides flanges for attachment of spring fastener features ; characterised in that the second seal wall includes a plurality of segments extending to a common, first radial location and a plurality of recessed portions extending to a second radial location that is radially inward of the first radial location; and each of the plurality of recessed portions extends circumferentially between an adjacent pair of the plurality of segments . a first seal wall , a second seal wall and a base seal wall , the first seal wall , the second seal wall and the base seal wall defining a groove for receiving the seal therein, the second seal wall extending radially outwardly to a non-uniform radial location; wherein the main plate portion defines anti-rotation slots and provides flanges for attachment of spring fastener features ; characterised in that the second seal wall includes a plurality of segments extending to a common, first radial location and a plurality of recessed portions extending to a second radial location that is radially inward of the first radial location; and each of the plurality of recessed portions extends circumferentially between an adjacent pair of the plurality of segments . <EOS>