A liner for a gas turbine engine, comprising: an outer wall; an inner wall; wherein the outer wall is spaced apart from the inner wall and is disposed radially outside of the inner wall, the outer wall and inner wall forming an annular structure having a circumference, and an annular region disposed between the first interior surface of the outer wall and the second interior surface of the inner wall; and a plurality of structural elements disposed between the inner wall and the outer wall, and each of the plurality of structural elements is attached to the outer wall and the inner wall; wherein the outer wall includes at least one inspection port extending through the outer wall configured for access to the annular region disposed between the first interior surface of the outer wall and the second interior surface of the inner wall; wherein the plurality of structural elements extend around the circumference of the annular structure, and define a plurality of independent annular sub-regions, and at least one of the independent annular sub-regions includes the at least one inspection port disposed in a portion of the outer wall of the respective one of the independent annular sub-region, the at least one inspection port is a plurality of said inspection ports, each said inspection port having a first area, and the collective first areas is a second area, the respective one of the independent annular sub-regions includes a plurality of first cooling apertures disposed in the outer wall portion; and wherein the first cooling apertures disposed within the outer wall portion have a collective third area, and the second area is less than about ten percent (10%) of the third area. an outer wall; an inner wall; wherein the outer wall is spaced apart from the inner wall and is disposed radially outside of the inner wall, the outer wall and inner wall forming an annular structure having a circumference, and an annular region disposed between the first interior surface of the outer wall and the second interior surface of the inner wall; and a plurality of structural elements disposed between the inner wall and the outer wall, and each of the plurality of structural elements is attached to the outer wall and the inner wall; wherein the outer wall includes at least one inspection port extending through the outer wall configured for access to the annular region disposed between the first interior surface of the outer wall and the second interior surface of the inner wall; wherein the plurality of structural elements extend around the circumference of the annular structure, and define a plurality of independent annular sub-regions, and at least one of the independent annular sub-regions includes the at least one inspection port disposed in a portion of the outer wall of the respective one of the independent annular sub-region, the at least one inspection port is a plurality of said inspection ports, each said inspection port having a first area, and the collective first areas is a second area, the respective one of the independent annular sub-regions includes a plurality of first cooling apertures disposed in the outer wall portion; and wherein the first cooling apertures disposed within the outer wall portion have a collective third area, and the second area is less than about ten percent (10%) of the third area.