Los Zumacales

The tomb stands about 1700 metres north-east of the built-up area of Simancas, on the summit of a distinctive landform. This lies at the transition between the sandy farmland of the Pisuerga valley to the south and the southern edge of the limestone structure of the montes Torozos. The site is at 740 m altitude, about 60 m above the adjacent valley, and commands a wide view over the surrounding land, in particular over the confluence of the rivers Duero and Pisuerga.

The tomb has a single phase of construction and use, associated with an advanced stage of the Interior Neolithic. It consists of a central chamber, a corridor or passage, and an earthen mound that envelops and gives monumental form to the inner structure.

The chamber is circular, 5,20 m in diameter, with a stone plinth of about twenty roughly dressed limestone blocks, of which only 11 remain in situ. The blocks are laid flat and are around 80 cm thick. The corridor, oriented to the south-east, is now very degraded. In 1981 two of the limestone orthostats that formed it could still be recognised, but they were pulled out shortly afterwards. Excavation has nevertheless identified one slab in situ and the traces of three others, set in cuts in the bedrock.

The mound originally reached 30 m in diameter. It is built of earth and limestone pebbles arranged in three concentric sectors, bound by successive rings of stones: chamber buttresses of oblique slabs, a peristalith crown and stone casings that delimit, contain and reinforce the earthen mound.