The Arca da Piosa (megalithic tomb) Monument · Zas, Terra de Soneira, A Coruña A Arca da Piosa is a dolmen about five thousand years old located right on the boundary between the parishes of Muíño (Zas) and Baíñas (Vimianzo), with a polygonal chamber 3.20 metres wide formed by four orthostats and a cover, and a short one-metre passage facing east, closed by a laxe split into three pieces and covered in turn by another, larger slab; the total length of the monument is 8 metres, with large slabs, especially those covering it, and a very visible mámoa. It was studied in 1933 by the German archaeologist Georg Leisner and is well preserved; it lies close to other dolmens in the area, such as the Pedra Moura de Monte Carneo, the Pedra da Lebre and the Pedra Cuberta. It was declared Bien de Interés Cultural (Spain's highest level of heritage protection) in 2011. Photo: Javier Pais (CC BY 2.0) What to see and do in Zas