During the first phase of the Research Programme of Amykles, the focus of the excavational work was the research of the precinct wall (peribolos) that are found to the South, East and North of the Sanctuary. The objective was to reveal the construction in its full length, to define its limits and to solve any kind of dating problems, as well as those concerning later interventions and the more general structural development of the monument. During the excavation works between 2006 and 2009 it was possible to establish that the function of the precinct was basically that of a retaining wall. Constructed by local conglomerate stone, the form of this construction is adapted to the geomorphologic data of the hill, rendering any kind of special planning unnecessary. Even if until now only the southern end has come to light and still its course to the North has not been clarified, it can, however, be considered certain that the precinct had been built in the shape of a petal on the steepest slopes of the hill. While researching the northern section, it was possible to find out that, due to the structure of natural rocks, the precinct must have undeniably extended in a North-Westerly direction. The remaining sizes of the monument are the following: 116 metres of length, two metres in height and two and a half metres of width. Its foundations descend to a depth of 200 metres above sea level. According to metrological analyses, its most characteristic section on the south side reaches 100 Doric feet which corresponds to a hekatompedon. This intentional and emphatic configuration is probably directly related to the procession that took place at Hyakinthia. The bulky structure and the extensive width of the precinct allow for the assumption that this construction had initially a height from six to seven metres, and that it must have reached the level of the still visible foundation on the top of the hill. In this way, a vast area around the throne was created, and that of course assisted the process of cult celebrations, as well as the facility of constructing other buildings as time passed. In the monument, successive restorations and preservations of later years can be observed. Tsountas, as well as Buschor - Massow have been led to this conclusion. With regard to the later interventions it should, finally, be mentioned that the monument bears traces which lead to information on its extension and repair, but also to more general measures of maintenance which must had been carried out during the Roman and Byzantine period.
About six and a half metres North of the South-Eastern end of the precinct wall the last section of an unknown –so far- wall came to light, that had been built on the porous, natural surface of the hill. Its axis has a north-eastern direction, with a divergence of almost 5 degrees from the classic precinct. This new construction is made of roughly processed stones that have been placed with particular attention only on the front side, while on its back side, it is developed gradationally in two different hypsometric levels and they constitute a filling. With 30 metres in length and 2.10 metres in width, it is a bulky and compact construction that functioned, like the classic precinct, at the same time as an analemma (retaining) wall and a precinct. The lack of clear stratigraphy, however, hinders any attempt to date it. The way in which it has been constructed points to it having been built in the Late Geometric or early Archaic period. Together with the majority of the pottery findings this is, therefore, data relevant to the first or early monumental phase of the Amyklaion sanctuary, which most certainly was directly interwoven with the existence of an open-space cult activity and a corresponding cult statue. This opinion is also strengthened by a thin layer of ash that was found at ground level on the whole front side of the wall. The destruction of this construction is possibly dated to the second quarter of the 5th century B.C. The concave section that is evident in its eastern end is an explicit indication of the consequences of an earthquake that most probably took place in 464 B.C. which is described with particular detail by Plutarch (Kimon 16, 4).