Segedunum Segedunum was a Roman fort at modern - day Wallsend , Tyne and Wear , England , UK . The fort lay at the eastern end of Hadrian ' s Wall ( in Wallsend ) near the banks of the River Tyne , forming the easternmost portion of the wall . It was in use as a garrison for approximately 300 years , almost up to 400AD . Today , Segedunum is the most thoroughly excavated fort along Hadrian ' s Wall , and is operated as Segedunum Roman Fort , Baths and Museum . History . The Roman wall originally terminated at Pons Aelius ( Newcastle upon Tyne ) . Work began at Pons Aelius in 122AD and proceeded towards the west . Subsequently , in about 127AD , the wall was extended further east , possibly to protect the river crossing at Pons Aelius . A four - mile section of the wall east from the fort of Pons Aelius , passing through present - day Byker and ending at the new fort of Segedunum was built . The new section of wall was narrower than the sections previously built , being on a foundation of . Unlike the rest of the wall , the extension had no vallum . The fort measured from north to south and from east to west , covering an area of . A wide ditch and an earth embankment surrounded the fort on all sides . It had four double gates with the east , west and north gates opening outside the wall and only the south gate opening within the wall . The wall joined to the west wall of the fort just south of the west gate . From the southeast angle of the fort , a wide wall ran down to the riverbank and extended at least as far as the low water level . There is evidence that there was an extensive vicus , or village surrounding the fort , including the area to the north of the wall . Garrison . The original garrison of Segedunum is unknown , but in the 2nd century the Second Cohort of Nervians was stationed there . In the 3rd and 4th centuries the part - mounted Fourth Cohort of the Lingones occupied the fort , as recorded in the Notitia Dignitatum . Both units were 600 strong . 120 cavalry and 480 infantry [ 2 ] Subsequent history . Sometime round about 400AD the fort was abandoned . For centuries the area remained as open farmland , but in the 18th century , collieries were sunk near the fort and the area gradually became a populous pit village . Eventually , in 1884 , the whole fort disappeared under terraced housing . In 1929 some excavations were carried out which recorded the outline of the fort . The local authority marked out this outline in white paving stones . In the 1970s the terraced houses covering the site were demolished . A section of Hadrian ' s Wall was excavated and a reconstruction built in the early 1990s . The Segedunum project began in January 1997 with a series of excavations in and around the Fort , as well as the construction of the bath house and the conversion of former Swan Hunter shipyard buildings to house the new museum . Segedunum Roman Fort , Baths & Museum opened to the public in June 2000 . Today . The site of the fort now contains the excavated remains of the buildings ' foundation of the original fort , as well as a reconstructed Roman military bathhouse based on excavated examples at Vindolanda and Chesters forts . A museum contains items of interest that were found when the site was excavated and a large observation tower overlooks the site . A portion of the original wall is visible across the street from the museum , and a reconstruction of what the whole wall might have looked like . This eastern portion of Hadrian ' s Wall was erected atop the Whin Sill , a geological formation that offers a natural topographic defence against invaders or immigrants from the north . North Tyneside Council provided accommodation in the newly built Battle Hill Estate for the owners of all the houses demolished . The name Wallsend comes from Sedgedunum being at one end of the wall . Etymology . The name " Segedunum " is known from the " Notitia Dignitatum " of the 4th century , but there is no consensus on its meaning . The various conjectures include " derived from the Celtic for ' powerful ' or ' victorious ' " , " derived from the [ Celtic ] words " sego " ( ' strength ' ) and " dunum " ( ' fortified place ' ) " , " Romano - British " Segedunum " ' Strong - fort ' " , and " Celtic " sechdun " or ' dry hill ' " .