A bunk, in particular for a vehicle cabin, comprising: - a base plate; - an upper layer; - a plurality of supporting members which are vertically compressible, such as springs, the supporting members being arranged spaced apart from one another, according to an array, substantially over the whole surface of the bunk; - a plurality of pressure sensors which are part of the upper layer and arranged in at least one area of the bunk called adaptable area; - a moving mechanism connected to at least some of the supporting members located in the adaptable area; - a control unit connected to the pressure sensors and to the moving mechanism, the control unit being configured to cause the moving mechanism to automatically and dynamically move the supporting members in the adaptable area, as a function of the current pressure data provided by the pressure sensors, characterized in that the moving mechanism is configured to move said supporting members with respect to and parallel to the base plate, so as to locally change the density of the supporting members, i.e. the number of supporting members per area unit of the base plate, in order to provide a locally variable bunk firmness, and in that two adjacent supporting members in the adaptable area are linked by both an elastic connection and a non-extendable connection, wherein: - in a neutral state, the elastic connection is pre-tensioned and further extendable, and the non-extendable connection is loose, thus inactive for motion transmission; - from the neutral state, the adjacent supporting members can be moved relative to one another when an appropriate action is applied by the moving mechanism on the supporting members, the elastic connection then being further extended and the non-extendable connection then being fully taut, thus able to transmit the motion of one of said supporting members, caused by the moving mechanism, to the other one of said supporting members; - and these adjacent supporting members can elastically return to the neutral state by means of the elastic connection, when said action is released. - a base plate; - an upper layer; - a plurality of supporting members which are vertically compressible, such as springs, the supporting members being arranged spaced apart from one another, according to an array, substantially over the whole surface of the bunk; - a plurality of pressure sensors which are part of the upper layer and arranged in at least one area of the bunk called adaptable area; - a moving mechanism connected to at least some of the supporting members located in the adaptable area; - a control unit connected to the pressure sensors and to the moving mechanism, the control unit being configured to cause the moving mechanism to automatically and dynamically move the supporting members in the adaptable area, as a function of the current pressure data provided by the pressure sensors, - in a neutral state, the elastic connection is pre-tensioned and further extendable, and the non-extendable connection is loose, thus inactive for motion transmission; - from the neutral state, the adjacent supporting members can be moved relative to one another when an appropriate action is applied by the moving mechanism on the supporting members, the elastic connection then being further extended and the non-extendable connection then being fully taut, thus able to transmit the motion of one of said supporting members, caused by the moving mechanism, to the other one of said supporting members; - and these adjacent supporting members can elastically return to the neutral state by means of the elastic connection, when said action is released.