The ongoing excavations on the summit of Papoura Hill, Crete, conducted at a height of 494 m, to the north-east of Kastelli and the construction site of the new airport, have yielded a monumental architectural complex of circular shape, which is unique for the Minoan archaeology. It has a diameter of approximately 48 m, covering an area of about 1,800 sq.m. It lays at the highest point of the hill, in an area of the summit that had been expropriated in order to install a radar system for the new airport.

The monumental structure consists of 8 concentric stone rings – which have an average thickness of 1.40 m and an estimated preserved height of 1.7 m –, on different height levels. In the centre of the rings, there is a circular building (zone A) with a diameter of 15 m and a corbelling masonry, the interior of which (diameter: 9 m) is divided in four quadrants. Zone A is surrounded by a second main zone (zone B, max. width: 6.9), in which radial walls vertically intersect the rings of the lower levels creating smaller spaces. On the course of excavations, an almost labyrinthine structure came to light, as the different spaces of the complex connect through narrow openings. On the SW and NW profile, two possible entrances to the central zones have been revealed.

The structure was used mainly between 2000 and 1700 BC, which means that it was possibly built  shortly before or during the Palaeopalatial period (MMI-II), while the presence of neopalatial pottery in the destruction layer suggests that the use of the monument continued during the Neopalatial period.

The groundplan of the monument and its division in zones and areas has no parallels of the same period on Crete. However, its shape can be found in examples of the Early Bronze Age in the Near East. It could perhaps be paralleled  with the elliptical MM building of the Chamezi Archaeological Site (Crete), as well as with the so-called circular Proto-Hellenic Cyclopean building of Tiryns. Structural similarities can be also detected with the so-called tholos tombs of the Prepalatial and Paleopalatial periods in southern Crete, in which the central area was constructed with a corbelling masonry. Furthermore, the whole structure reminds us of Protohelladic burial mounds of central Greece and circular sanctuaries of later periods, e.g. thesmophoria.