In order to supplement missing information regarding the methods used to support the wall and the state of preservation of its foundations, underwater and coastal archaeological inspections were conducted accompanied by engineering and conservation work. During the trial excavations, several of the wall’s construction phases were discerned and the foundations of an earlier wall and remains of buildings were exposed; these were used as foundations for the Ottoman wall. In addition to these, sections of the seawall founded on an artificial embankment built of fieldstones and mortar were exposed. Ancient columns placed in secondary use on the embankment served to reinforce the foundations. A water pump and dredger suitable for underwater archaeological excavations were implemented in the offshore probes, and backhoe was employed to excavate four trial trenches on land. The probes included trial trenches at the foot of Khan esh-Shawarda, near the sea (Hof Ha-Susim), and an underwater excavation where the eastern seawall meets the Burj el-Sultan tower (Fig. 1:1–5).
Trench 1 (map ref. 207041/758530; length 3 m; Fig. 1:1). The trench was excavated adjacent and parallel to the seawall, c. 4 m from the water line. On the bedrock, reached at a depth of 2.3 m bsl, were three courses of dry construction that carried the seawall facade. Ancient building stones, pebbles and a large amount of modern debris were removed during the excavation. Five courses of dry construction of medium-sized ashlars (c. 0.3–0.4 m) could be discerned; the top course was found beneath the sand. The bottom three courses of the wall protrude outward c. 0.10–0.15 m relative to the upper two courses. Due to the proximity to the sea, the water level in the trial trench rose rapidly, and waves penetrated and covered the trench.
Trench 2 (map ref. 207046/758377; length 3 m; Fig. 1:2). The trench was excavated adjacent and parallel to the seawall. Bedrock was exposed at a depth of 2.3 m bsl. The first course, built of dry construction utilizing large dressed stones (Fig. 2), was founded on the bedrock. The three courses above it protrude from the line of the wall (width c. 0.10–0.15 m); these courses are also of dry construction, but consist of various-sized dressed stones. Above these courses and below the level of the cement bags and sand were two more courses built of dressed stones. In the upper parts of this section of the wall (at sea level and above) conservation measures comprised pointing up the stone joints with cement. Two courses of cement bags were also placed at the base of the wall so as to protect it from the action of the waves.
Trench 3 (map ref. 207050/758542; length 1 m; Fig. 1:3). The trench was excavated adjacent and parallel to the seawall. Bedrock was exposed at a depth of 2 m bsl (Fig. 3). The first course, founded on the bedrock, included a long, dressed stone, the largest one observed to date in the foundations. Irregular fieldstone construction was exposed above this course (c. 1.9 m bsl), up to the elevation of the concrete belt (c. 0.4 m asl). The poured-concrete belt (width c. 0.4 m, thickness c. 1 m), which adjoined the wall in an attempt to reinforce the structure, is composed of pebbles. Conservation was also done on the glacis above the concrete belt by filling the spaces between the stones with cement. Building stones, stone fragments, pebbles and modern refuse that had accumulated at the foot of the seawall were removed during the excavation.
Trench 4 (map ref. 207051/758545; length 3 m; Fig. 1.4). The trench was excavated perpendicular to the seawall, in a section where the concrete belt and cement bags are missing. Bedrock was exposed at a depth of 2 m bsl (Fig. 4). The seawall was founded on the bedrock; the four exposed courses were built of small and medium dressed stones. Numerous building stones and modern debris were removed during the excavation.
Underwater Probe 5 (Fig. 1:5). The probe was excavated near the southern corner of Burj el-Sultan and the seawall. The excavation was conducted within an aluminum frame (2 × 2 m). Bedrock was exposed at a depth of 2.6 m bsl. A layer of fill composed of various kinds and sizes of fieldstones (mainly kurkar) and dressed stones was exposed above the bedrock. A filling comprising a mixture of lime, pebbles, pottery sherds and animal bones was set between the stones. A layer containing mainly medium-sized kurkar fieldstones (c. 0.3–0.4 m) was exposed c. 1.6 m bsl. Surmounting this layer was a modern layer of conglomerate (thickness c. 0.5 m) composed of construction debris and pieces of iron; on the surface and above it was a layer of sand (thickness c. 0.10–0.15 m) and modern construction debris. Two courses of gray-black granite columns (diameter 0.5–0.6 m) placed horizontally were visible in the trial trench that was excavated in the foundations of the seawall (Fig. 5). Three columns could be discerned in the bottom course, and two columns—in the course above them (Fig. 6). The gaps between the columns were filled with small and medium fieldstones and mortar. Most of the filling material between the columns had been washed away, leaving deep cavities. A thick casting (1 m) of mortar, stones, pottery sherds and animal bones was exposed below the columns and extended as far down as the bedrock (2.6 m bsl). A similar situation was noted around the probe.
The foundations of the southern corner of Burj el-Sultan were exposed on the northeastern side of the trench (Fig. 7). Four courses built of dressed and smoothed kurkar stones (c. 0.4 × 0.4 m) and mortar were discerned. Traces of iron oxide were noted c. 0.1 m from the corner stone, probably indicating that the stones were joined together with iron fasteners. The bottom course was founded on bedrock. It seems that the foundations of Burj el-Sultan are c. 0.4 m wider than the tower. A gap (width 0.5 m) between the corner of the foundation column courses and the wall of Burj el-Sultan that is visible above the water was filled with mortar and stones. A wide space (width c. 1 m) between the foundation of Burj el-Sultan and the first course of columns was filled with stones and mortar. A sampling of the mortar was removed from the side of the trench at a depth of 1.6 m. Its composition was clearly identifiable: river sand mixed with gravel and small pebbles, pottery sherds, animal bones, lumps of kurkar and probably lime. In addition, part of a water-logged wooden beam was found incorporated in the mortar.
The trial trenches revealed five built courses beneath the sand. The foundation course, visible in Trenches 1 and 2, was built of large, dressed stones set on the bedrock, exposed at a depth of c. 2 m bsl (c. 2.3 m below the sand at the foot of the seawall). At least two construction styles were identified; they differ in stone size and in the degree of precision and uniformity in the laying the courses. The more ancient remains, most probably date to the Crusader period, are built of dry construction using large ashlars. The leveled and uniformly constructed courses of small ashlars resemble the upper courses of the wall from the time of Dahar al-Omar (1750–1751), which were repaired and improved by Jazaar Pasha (1775–1804). The differences in the construction style and technique might indicate that Khan esh-Shawarda, which was built in the eighteenth century CE, was partly founded on the remains of Crusader construction. The wall might continue as far as Burj el-Sultan—the square tower—as portrayed in the panoramic drawing depicting ‘Akko from the sea in 1686 CE.
The finds from the trial trenches show that the wall at Hof Ha-Susim was probably built in two phases; the first phase is likely part of the Crusader fortifications. The finds from the trial excavation indicate that Burj el-Sultan was erected during the Crusader period, and was founded on kurkar bedrock at a depth of 2.2 m bsl. Bedrock was discovered at this depth in the trial trenches as well. Evidently, the buildings of the Venetian Quarter adjacent to the Burj were destroyed during the Mamluk period. In the Ottoman period, the surface was raised, and Khan esh-Shawarda was built. Subsequent to raising the surface level, rehabilitating the Burj and adapting it for cannon fire, a new entrance, which corresponded to the elevation of the new habitation level, was opened. Above the entrance to the old tower is an inscription that was identified as Mamluk; consequently, it was erroneously assumed that the Burj was built during this period. The direction of the Crusader-period firing slits in Burj el-Sultan, which are suited for archers, seem to indicate that the tower protected the entrance to an inner anchorage that penetrated into the Venetian quarter; this anchorage appears on historical maps.