a group of ancient buildings has been uncovered by construction workers preparing a site for a 1916 exhibition and interpretive centre at the GPO.
Part of the main site of the historic Easter Rising is currently being excavated to make way for the new 1,550 sq metre project which will be called 'GPO: Witness History'.
But this week, when sections of paving were lifted and groundwork got underway, the outline of the remains of an old building started to emerge.
"We had an archaeologist survey the site before work began, and there was always one present during the works, because we knew it was likely that something might be underground at the site," a spokesperson for An Post told the Herald.
"We're not exactly sure yet what the building is but it could be an old sorting office that was there at the time of the Rising or it could be an 18th century building," they added.
"We have known that buildings that have long since vanished were standing at the time of the Rising, and with most of the site having been badly damaged in the shelling in 1916, it is possible this building was one of them."
The physical evidence shows a rectangular-shaped red-brick building. A long section of pipe, from a surface drain appears to cut through it and was most likely installed after the demolition of the building.
The area being excavated is in a courtyard behind the main block fronting onto O'Connell Street.
The GPO was designed by Francis Johnston, first president of the Royal Hibernian Academy, and was opened in 1818.
It had just undergone extensive modernisation a month before it became the headquarters of the insurgents during the 1916 Rising.