Complex sentence: He is believed to have camped near the Labour Exchange building on Mellowes Road and to the rear of Glebe House with access from Church Street, during excavation works at the site in the early 1990s they found what is believed to be fortifications dating from this time.
Split into simpler sentences: He is believed to have camped near the Labour Exchange building on Mellowes Road and to the rear of Glebe House with access from Church Street. Excavation works at the site in the early 1990s found what is believed to be fortifications dating from this time.