A combustor of an aircraft engine, comprising: a liner having a hot surface (26a, 26b) for being exposed to a flow of combustion gases and a cold surface (24; 26c, 26d), the liner defining a primary zone of the combustor and a dilution zone of the combustor, the combustor configured to cause the flow of combustion gases to travel through the combustor from the primary zone downstream to the dilution zone; a plurality of dilution holes extending through the liner from the cold surface (24; 26c, 26d) to the hot surface (26a, 26b), the plurality of dilution holes delimiting the primary zone from the dilution zone and having dilution hole diameters, the liner including a plurality of endwall contours, the plurality of endwall contours having a thickness greater than a thickness of a remainder of the liner, the plurality of endwall contours including a protrusion extending from the hot surface (26a, 26b) into the flow of combustion gases, the protrusion including an upstream wall extending from the hot surface (26a, 26b) and the protrusion including a downstream wall extending from the upstream wall toward the hot surface (26a, 26b) in a downstream direction relative to the direction of the flow of combustion gases; and a plurality of effusion holes extending through the liner from the cold surface (24; 26c, 26d) to the hot surface (26a, 26b) to direct cooling air into the dilution zone, two or more rows of effusion holes of the plurality of effusion holes positioned within three dilution hole diameters downstream of the plurality of dilution holes, the two or more rows of effusion holes (42a; 42b) oriented relative to the liner to direct the cooling air in a cooling direction that is at least one of normal to the direction of the flow of combustion gases passing adjacent the effusion holes, and against the direction of the flow of combustion gases passing adjacent the effusion holes, characterised in that: the endwall contours partially delimit the plurality of dilution holes; and the upstream wall of the protrusion delimits the plurality of dilution holes. a liner having a hot surface (26a, 26b) for being exposed to a flow of combustion gases and a cold surface (24; 26c, 26d), the liner defining a primary zone of the combustor and a dilution zone of the combustor, the combustor configured to cause the flow of combustion gases to travel through the combustor from the primary zone downstream to the dilution zone; a plurality of dilution holes extending through the liner from the cold surface (24; 26c, 26d) to the hot surface (26a, 26b), the plurality of dilution holes delimiting the primary zone from the dilution zone and having dilution hole diameters, the liner including a plurality of endwall contours, the plurality of endwall contours having a thickness greater than a thickness of a remainder of the liner, the plurality of endwall contours including a protrusion extending from the hot surface (26a, 26b) into the flow of combustion gases, the protrusion including an upstream wall extending from the hot surface (26a, 26b) and the protrusion including a downstream wall extending from the upstream wall toward the hot surface (26a, 26b) in a downstream direction relative to the direction of the flow of combustion gases; and a plurality of effusion holes extending through the liner from the cold surface (24; 26c, 26d) to the hot surface (26a, 26b) to direct cooling air into the dilution zone, two or more rows of effusion holes of the plurality of effusion holes positioned within three dilution hole diameters downstream of the plurality of dilution holes, the two or more rows of effusion holes (42a; 42b) oriented relative to the liner to direct the cooling air in a cooling direction that is at least one of normal to the direction of the flow of combustion gases passing adjacent the effusion holes, and against the direction of the flow of combustion gases passing adjacent the effusion holes, characterised in that: the endwall contours partially delimit the plurality of dilution holes; and the upstream wall of the protrusion delimits the plurality of dilution holes.