About 70 m east of the tip of the southern breakwater stands a structure known as the Tower of the Flies. The tower is laid on an artificial island, atop a platform of 60 m long and 17-18 m wide, that extends on a northeast and southwest axis. The northeastern part of the island is preserved almost up to the present sea level. The surviving upper course is built of ashlar header blocks similar to those in the outer face of the southern breakwater. Such building stones also may be seen in the foundation of the structure exposed on the southern edge, at a depth of 6 m bellow the sea level. During the underwater investigations of this artificial island, was observed a combined construction of headers and stretchers of irregular heights and widths.
Parallel and Date of the Tower of the Flies: The construction resembles the ancient quay of the port at Sidon, which is dated to the Hellenistic period (5th-4th century BCE). The earliest potsherds recovered from the excavations at Akko near the bottom of the island were dated to the Hellenistic period. The structure beneath the Tower of the Flies probably served as a pier.
The harbour parcels adjoined a road, approximately 3 m wide, which ran along the edge of the em-bankment from north to south, with the vicus situated behind it. Since little of the vicus has been excavated, the following outline cannot be more than a hypothesis.
The harbour parcels were continued into the vicus, which means that
it was also divided into plots, running from east to west. These were approximately
20 m wide and corresponded each with a couple of platforms in the riverbed.
Houses on these plots stood with their longitudinal axes towards the river.
These were rectangular, 6 m-wide wooden buildings, of which no further
details are known. Lengthwise, there was room for at least three houses,
one behind the other, with an average length of 20-25 m each. It is possible
that the houses had enclosed yards. The vicus might then have consisted
of three rows of houses parallel to the river, situated behind each ther.
Sections of platforms completely free of internal features are rare. In most cases, the inner space is marked by the presence of rows of vertical posts - with roughly a diameter of 15 cm - parallel to the long axis of the platforms. They might have been connected by planks or beams, fastened to the top, which probably served as foundations for the road pavement. The construction of the pavements itself remains obscure.
The complex of the platforms is the result of a long building process. The development started on the west bank of the river in approximately AD 675/700, from which the building activities spread to-wards the east, gradually penetrating into the river bed. The total complex of the harbour is made up of two parts: a western (Part 1) and an eastern (Part 2), characterised by a significant change in building-style. The division runs across the whole complex from north to south, at about the transition from squares A/K-8 to A/K-9 (see fig.3 and fig.4). To the west of this division, the sections are relatively narrow and often rather vaguely outlined, with mostly short compartments; well-defined rows of inner posts are rare. To the east, the platforms tend to be slightly wider, with clear outlines, many long compart-ments and well-defined inner post rows.
Part 1 is subdivided into two zones, the Sectors 1A and 1B, of which the transition corresponds roughly with the squares A/K 5.
1A is characterised by by several isolated, short but remarkably regular
ground plans (see fig.4). These substantially
built platforms (see the reconstructed platforms in fig.5
and fig.6) - some 10 or 12 m long and 6
to 7 m wide - represent the starting points in the development of the whole
complex. Most of them were extended afterwards by the addition of new compartments.
1B is characterised by its `vagueness' (fig.7).
The not easily definable platform sections probably represent comparatively
In Part 2 the complex acquires its definite form, with a relatively regular system of well defined, substantially built platforms. The length of the compartments and the regularity of the general layout suggest a more rapid growth than in Part 1.
Part 2 also shows a subdivision into successive zones, but of minor
importance, as the difference between the individual sectors is far less
pronounced than in Part 1. Three zones are distinguishable: Sector 2A (division
line with 2B mainly through squares A/K-16), Sector 2B (division line with
2C mainly through squares A/L-18/19) and Sector 2C.
2A (see fig.8) shows unusually long compartments
(see the reconstructed cause-ways on fig.9
and fig.10), extending nearly as far as
square 17, with their eastern ends forming an almost straight line, from
north to south. Sector 2A is dated to approximately AD 700/725-750/775.
2B (see fig.11) has compartments rather
shorter than those in Sector 2A, but the difference is not great. This
sector is dated to approximately AD 750-775.
2C (see fig.12) represents the end of the
development of the harbour. It shows a re-markable change, since the compartments
are now extremely short. The eastern edge presents a frayed and ragged
line, caused by substantial erosion. The excavators presume however, that
the eastern edge in reality represent the original end of the platforms.
Period 2C is to be subdivided in:
1b, the extensive port installations consisted of a platform, projecting
into the river and placed centrally in the encircled river shore (see also
From this platform, two moles extended further into the river, which more
or less defined an `outer' harbour.
It is possible that along the easternmost mole, defended by the eastern riverside defences, non-Roman (Friesian?) ships could unload. The central platform with its moles and the undefended western riverside section that gave access to the shipshed, were undoubtedly only accessible for use by Roman ships.
1c, the harbour was modified. This was necessary, due to scouring at
the west side of the platform (see fig.12:
rendered in blue) and silting in between the platform-moles and at the
east side of the platform (fig.12: rendered
in yellow). It is obvious, that the moles will have contributed to a partial
stagnation of the Oer-IJ current. The scouring also weakened the revetments
of the moles.