A mattress which in plan view comprises an inner portion and an outer portion, the mattress being such that the inner portion is of a size for being slept on by at least one person, the outer portion extends at least partially around the inner portion, and the inner portion has a lower compression rate than the outer portion whereby the weight of the person on the inner portion is distributed over a greater area than would be the case if the inner portion had the same compression rate as the outer portion, and whereby the outer portion constrains the inner portion and controls lateral deformation of the inner portion caused by the weight of the person on the inner portion, and the mattress being characterised in that: (i) the inner portion is in a shape which has a first part for receiving the head of a sleeping person, a second part for receiving the feet of the sleeping person, and a third part for receiving the buttocks of the sleeping person; (ii) the first part and the second part are narrower than the third part; (iii) the first part and the second part are sufficiently wide that the first part is able to be for receiving the feet of the sleeping person and the second part is able to be for receiving the head of the sleeping person, whereby the mattress is able to be turned through 180° with its same side uppermost for facilitating uniform wear of the mattress and prolonged life of the mattress; (iv) the inner portion comprises a plurality of apertures which define the shape of the inner portion; (v) the apertures extend completely through the mattress whereby the underside of mattress also has the inner portion, whereby the mattress is able to be turned over so that its underside becomes its topside and thereby becomes able to receive the sleeping person and thereby further facilitates the uniform wear of the mattress and the prolonged life of the mattress; (vi) the first part and the second part are of the same shape; and (vii) the inner portion is symmetrical about a longitudinal centre of the mattress, and also about a transverse centre of the mattress. (i) the inner portion is in a shape which has a first part for receiving the head of a sleeping person, a second part for receiving the feet of the sleeping person, and a third part for receiving the buttocks of the sleeping person; (ii) the first part and the second part are narrower than the third part; (iii) the first part and the second part are sufficiently wide that the first part is able to be for receiving the feet of the sleeping person and the second part is able to be for receiving the head of the sleeping person, whereby the mattress is able to be turned through 180° with its same side uppermost for facilitating uniform wear of the mattress and prolonged life of the mattress; (iv) the inner portion comprises a plurality of apertures which define the shape of the inner portion; (v) the apertures extend completely through the mattress whereby the underside of mattress also has the inner portion, whereby the mattress is able to be turned over so that its underside becomes its topside and thereby becomes able to receive the sleeping person and thereby further facilitates the uniform wear of the mattress and the prolonged life of the mattress; (vi) the first part and the second part are of the same shape; and (vii) the inner portion is symmetrical about a longitudinal centre of the mattress, and also about a transverse centre of the mattress.