Titus Tunnel

The Titus Tunnel is a pair of Roman Tunnels commenced by Vespasian in 69 CE and completed by Antoninus Pius in 161 CE. It includes a section of Canal.
It is located in Syria, 15 miles (24km) from Antioch.

The Tunnels and Canal were built in the Port city of Seleucia of Pieria in Syria, on the Mediterranean.
The Port was the Base for the Roman Navy, the Classis Syriaca, and was connected by a road linking to the Capital Antioch.
The Titus Tunnel was commenced by Vespasian (69-79 CE), it was continued by his son Titus (79-81 CE), but not actually completed until Antoninus Pius (138-161 CE).

The Canal was built to divert the upper River that caused damage when it flowed through the lower city during the flood season, and silted up the Inner Harbour.
The Canal was designed to divert the river away from the city, through the two tunnels, after which the canal then emptied into the Outer Harbour.

The Tunnel was designed by engineers from the Legio X Fretensis, and was completed by Legionaries from the Legio IIII Scythica and Legio XVI Flavia Firma.
The workforce consisted of Roman Legionaries, as well as the prisoners of war from the First Jewish-Roman War (66-73 CE), according to Josephus (37-100 CE).

The total length of the structure is 2,870 ft (875m).
A Roman dam was constructed in masonry to divert the upper stream, and is 59 ft (18m) high by 160 ft (49m) wide, backed by a sloping embankment 413 ft (126m) long.
The First Tunnel is 295 ft (90m) long, built in a horseshoe shape, it is 22 ft (6.9m) wide and 21 ft (6.5m) high at the exit.
The connecting open Canal between the two tunnels is 210 ft (64m) long, 18 ft (5.5m) wide, and is 82-98 ft (25-30m) in height.
The Second Tunnel is 101 ft (31m) long, built in a rectangular shape, 24 ft (7.3m) wide, and is 23 ft (7.2m) in height.
Running inside both tunnels on one side is a raised cistern, 1 ft (0.3m) in height and over 1 ft (0.4m) in width, to carry fresh spring water outside of the flood season.
An arched bridge, 14 ft (4.5m) high and spanning 18 ft (5.5m), carried an aqueduct over the canal.
The discharge canal into the Sea is 2,083 ft (635m) length, 12-23 ft (3.8-7.2m) in width and up to 49 ft (15m) in height.

The Tunnel is one of the most amazing feats of Roman engineering, built through solid rock, and the Site can be walked today.
The canal and tunnel structure is a total of one mile (1,400 m) long, and consists of two tunnels combined with the canal that emptied into what was the Roman outer harbour, but today runs into the sea.
A canal connected the Outer Harbour to the Inner Harbour, where the Roman Naval Fleet of Syria was based, the Classis Syriaca.
The tunnels bear two Latin inscriptions, one dedicating the Tunnel to the Emperors Vespasian and Titus, another dedicating the tunnel to Antoninus Pius.
The canal is dry today. Starting from where it empties into the sea, the first part of the canal is in the open. Before entering the tunnel, the canal is crossed by a Roman Bridge. It then enters a ravine, followed by the two tunnels.

The Besikli Magarasi (Cave with a Crib), which consist of 12 Roman Rock tombs with reliefs carved into the mountainside, are 328 ft (100m) from the upper end of the Tunnels.
They date from between the 1st-5th centuries CE.

There was a nearby Roman Road connecting Seleucia of Pieria with Antioch, the Capital of Syria.

Titus Tunnel