A portable mattress (100,200) comprising: a first layer (110,210) having a central portion (112,212), a first end portion (114,214) and a second end portion (116,216), wherein the central portion (112,212) extends in a lateral and a longitudinal direction, the central portion (112,212) has a first surface (118,218) and a second surface (120,220), and the first end portion (114,214) and the second end portion (116,216) extend from the central portion (112,212) at a first longitudinal edge (124,224) and a second longitudinal edge (128,228) of the central portion (110,210), respectively; a second layer (150,250) attached to the first layer (110,210), the second layer (150,250) being arranged in abutment with the second surface (120,220) of the central portion (112,212) of the first layer (110,210); fastening means (105,205) arranged to allow connecting: - a circumferential edge (122,222) of the first end portion (114,214) of the first layer (110,210) to the first longitudinal edge (124,224) of the central portion (112,212) of the first layer (110,210), - a circumferential edge (126,226) of the second end portion (116,216) of the first layer (110,210) to the second longitudinal edge (128,228) of the central portion (112,212) of the first layer (110,210), - a first lateral edge (130,230) of the central portion (112,212) of the first layer (110,210) to the first surface (118,218) of the central portion (112,212) of the first layer (110,210) along a laterally extending portion (132,232) of the first surface (118,218), such that the mattress (100,200), when rolled up with the first surface (118,218) of the first layer (112,212) facing outwardly, is configurable into an essentially cylindrical structure by fastening the fastening means. a first layer (110,210) having a central portion (112,212), a first end portion (114,214) and a second end portion (116,216), wherein the central portion (112,212) extends in a lateral and a longitudinal direction, the central portion (112,212) has a first surface (118,218) and a second surface (120,220), and the first end portion (114,214) and the second end portion (116,216) extend from the central portion (112,212) at a first longitudinal edge (124,224) and a second longitudinal edge (128,228) of the central portion (110,210), respectively; a second layer (150,250) attached to the first layer (110,210), the second layer (150,250) being arranged in abutment with the second surface (120,220) of the central portion (112,212) of the first layer (110,210); fastening means (105,205) arranged to allow connecting: - a circumferential edge (122,222) of the first end portion (114,214) of the first layer (110,210) to the first longitudinal edge (124,224) of the central portion (112,212) of the first layer (110,210), - a circumferential edge (126,226) of the second end portion (116,216) of the first layer (110,210) to the second longitudinal edge (128,228) of the central portion (112,212) of the first layer (110,210), - a first lateral edge (130,230) of the central portion (112,212) of the first layer (110,210) to the first surface (118,218) of the central portion (112,212) of the first layer (110,210) along a laterally extending portion (132,232) of the first surface (118,218), - a circumferential edge (122,222) of the first end portion (114,214) of the first layer (110,210) to the first longitudinal edge (124,224) of the central portion (112,212) of the first layer (110,210), - a circumferential edge (126,226) of the second end portion (116,216) of the first layer (110,210) to the second longitudinal edge (128,228) of the central portion (112,212) of the first layer (110,210), - a first lateral edge (130,230) of the central portion (112,212) of the first layer (110,210) to the first surface (118,218) of the central portion (112,212) of the first layer (110,210) along a laterally extending portion (132,232) of the first surface (118,218), such that the mattress (100,200), when rolled up with the first surface (118,218) of the first layer (112,212) facing outwardly, is configurable into an essentially cylindrical structure by fastening the fastening means.