Three pairs of stone piers divided the internal space into a series of bays, alcoves and recesses, which surrounded two large hearths in the centre of the northern and southern halves. Access was by three entrances, one of which was flanked by a pair of standing stones and faced Maeshowe.
The building has a chequered history. Featuring exquisite carved and dressed stone in its original construction, Structure Twelve must have been a stunning sight — and this presumably reflected its role within the complex.
Unfortunately this did not last long.
Structure Twelve was built on top of earlier structural remains. These shaky foundations saw the catastrophic collapse of the southern end and a complete, but poor-quality, rebuild.
This saw two of the original entrances blocked up and a new door inserted into the centre of the northern wall. At the same time an annexe was added but this construction project was decidedly shoddy.
This inferior rebuild appears to have marked a change to a more practical function, with evidence for cooking and stoneworking.
Around 2700BC, Structure Twelve was abandoned after another collapse.