The mámoa is a tumulus, an artificial accumulation of soil and stones raised over a burial site and sometimes containing a dolmen. This type of funerary monument was typical of the period between the Neolithic and the Bronze Age.

The Reira tumulus is located in front of the beach of the same name and it is easily accessed by following the PRG-158 Costa da Morte route starting in Camariñas and running along the coast.