Wikipedia
Nidum (or NIDVM) is a Roman fort found near the town of Neath, in Wales. An Auxiliary fort first built in around 74AD from earth banks and wooden structures, it underwent a reduction in size from 3.3 to 2.3 ha soon afterwards. It may have been garrisoned by perhaps 500 Auxiliary troops. It was abandoned in around 125AD, but re-occupied around 140AD when it was rebuilt in stone. However it was only occupied until 170AD, with 100 years of disuse before a final period in use from AD 275 and 320.
Much of the site is in the grounds of Dwr-y-Felin Comprehensive School, where a 2011 dig found gate-towers that extended out beyond the wall line, unique in Britain for its time, suggesting extreme defensive measures needed to be taken against the hostile Silures.
The site was first identified in 1949, and various excavations related to school or other building works took place in 1950, 1958, 1962, 1984-5. Finds recovered from these digs included roof and floor tiles, pieces of a 1st-century amphora, fragments of kitchen- and table-ware ranging in date from the earliest construction phase to the early-2nd century. One or two pieces are from the mid-2nd century. Six coins were also found, ranging from Augustus (Imp. 23B.C. - A.D.14) to Trajan (Imp. A.D.98-117). Some of the artifacts from the site are on permanent exhibition in the Neath Museum. The site is a Scheduled Ancient Monument.