Crucuno dolmen is one of the most well known dolmens in the Brittany. The rectangular chamber is about 4 metres by 3.5 metres, covered by a single massive capstone which measures over 7 metres in length, perched on top of 9 support stones, with easily enough room to stand upright inside. The enormous capstone is 7.6 metres in length and weighs about 40 tons. Unfortunately, a century or so ago, a house was built right next to it, and this has destroyed all but the last pair of entrance passageway uprights and their capstone. This passageway was recorded in the last century as being 20-25 metres in length, leading away towards the southeast.References:
The Naveta d"Es Tudons is the most remarkable megalithic chamber tomb in the Balearic island of Menorca.
In Menorca and Majorca there are several dozen habitational and funerary naveta complexes, some of which similarly comprise two storeys. Navetas are chronologically pre-Talaiotic constructions.
The Naveta d"Es Tudons served as collective ossuary between 1200 and 750 BC. The lower chamber was for stashing the disarticulated bones of the dead after the flesh had been removed while the upper chamber was probably used for the drying of recently placed corpses. Radiocarbon dating of the bones found in the different funerary navetas in Menorca indicate a usage period between about 1130-820 BC, but the navetas like the Naveta d"Es Tudons are probably older.
The shape of the Naveta d"Es Tudons is that of a boat upside down, with the stern as its trapezoidal façade and the bow as its rounded apse. Its groundplan is an elongated semicircle. Externally, the edifice is 14.5 m long by 6.5 m wide and 4.55 m high but it would originally have been 6 m high.
The front, side walls and apse of the edifice consist of successive horizontal corbelled courses of huge rectangular or square limestone blocks dressed with a hammer and fitted together without mortar, with an all-round foundation course of blocks of even greater size laid on edge.