A module (1, 16, 19, 28, 50, 52, 54, 100) for the creation of assemblies comprising at least one active magnetic element of attraction (2, 3, 17, 20, 33, 34, 42, 47, 48) and at least one ferromagnetic element (6, 21, 22, 30, 40, 44) suitable for defining areas (13, 14, 35, 36, 88, 90, 80, 82, 110, 10, 250, 260, 92, 94) for connection to other modules, with which it is possible to create an assembly of modules (1, 16, 19, 28, 50, 52, 54, 100, 37, 15) which provides a magnetic circuit which closes totally or at least partially via the ferromagnetic elements present (6, 21, 22, 30, 40, 44, 55, 104, 37, 15).