By Courtney Trenwith
A cobblestone street and horse stables from Brisbane's pioneering past have been discovered during excavation work at City Hall.
The relics, believed to date back as far as the 1850s, are the most significant archaeological finds in the city's history.
Workers at the excavation site yesterday - mid-19th century drain, right, was among the treasures found.Credit: Brisbane City Council
Construction workers uncovered the area four weeks ago while digging below the hall auditorium as part of a $215 million refurbishment of the historic building.
Further, careful excavation also uncovered an intact drain, building roofs, old horse shoes and bottles.
Brisbane City Hall before restoration started.
University of Queensland archaeology students are assisting three archaeologists contracted as part of the reconstruction project to ensure the integrity of the historic area.
Archaeologist Phil Habgood said details of the city's past spanning as much as 80 years, up until City Hall was built in 1930, could lie underneath the historic building.
"We've got evidence of corrugated iron buildings [underneath City Hall]," he said.
"The buildings were made from porphyry [stone] then they added concrete and bitumen throughout the area. We think there's probably a large 1850-60s stone drain.
"We've only got a very small section of the story so far."
The area already unveiled runs the full 50-metre length of the hall from Ann to Adelaide streets and spreads 15 metres wide.
"There's potential that the streetscape will continue right across the auditorium. There's nothing like that in Brisbane," Mr Habgood said.
"We're clearing and cleaning up the street surface and then tomorrow we're going to start drawing it so we've got a drawing record of it."
Lord Mayor Campbell Newman said more historic discoveries were likely as reconstruction work continued.
Many of those items would become part of the new Visitor Experience Centre, opened this morning.
“Photographs, video footage and other presentations will inform visitors about City Hall’s history and the restoration project currently being undertaken,” Cr Newman said.
“I invite visitors to share their memories of City Hall, experience a virtual tour, view and touch samples of building materials and take souvenir photos. Children will enjoy putting together a magnetic jigsaw puzzle.
“Interesting discoveries are often being made during the restoration project and this centre will enable us to showcase those finds to the community.”
Reconstruction of City Hall was instigated several years ago when it was revealed the public building was riddled with concrete cancer and had fire safety issues, mechanical and electrical faults and subsidence issues.
The restoration, which includes a kitchen five metres below the auditorium, where the streetscape has been discovered, is due for completion in late to mid 2012.
However, a spokesman for Lord Mayor Campbell Newman said today the historic discoveries had slowed work and could delay the project's completion.
Mr Habgood said he would discuss with council and the state government whether the street could be saved.
"The plan was to remove another [three metres] of earth, which means the streetscape may potentially have to be removed," he said.
"I'd like to talk to the project team about ... keeping it so sections of it may be visited as part of the Museum of Brisbane."
In 2008, a World War II signature wall was discovered in the building's basement.