Abstract: Disclosed is a panel that is produced by assembling a plurality of adjacent individual absorption blocks; each block in the panel is in the shape of a polyhedral pyramid frustum, of which the base is a regular six-sided polygon; each individual block including six lateral walls surrounded by a lower peripheral lip of which each section is provided with a complementary tenon or a mortise arranged so as to allow two adjacent individual blocks to be assembled, in particular by engagement, in the vertical direction, of a tenon and a mortise belonging respectively to one and the other of the two adjacent individual blocks.