Inside mysterious find underneath Australia Post building

For years the underground use of the heritage-listed building has been questioned.

Footage has revealed the inside of a bizarre trap door located inside a Brisbane Australia Post building, with rumours swirling that it could've been secretly used during World War II.

The 1879 heritage-listed General Post building on Queen Street — located where a structure once stood for female inmates — is now used by Australia Post and casually holds the trap door in one of the offices.

For years now people have theorised that it was part of underground escape tunnels throughout streets in the CBD, seemingly built by American General Douglass MacArthur.

A random trap door in a Brisbane 1879 heritage building that is now in use by Australia Post has left many wondering about its use.
A random trap door in a Brisbane 1879 heritage building that is now in use by Australia Post has left many wondering about its use. Source: 7News

"There's all this speculation that it was used for a wider network from WWII,” Suzanne Roberts from Australia Post told 7 News.

As she opens the door in the office space to reveal what's inside, a narrow space can be seen with a set of stone stairs, brick walls and a metal panelled ceiling. The rectangular area, which is now closed off, is speculated to once belong to a wider network of tunnels.

During World War II, the front of the heritage building was used for military parades, and is located near what is now called the MacArthur Chambers — in honour of General MacArthur who was hosted in Brisbane in 1942. MacArthur Chambers was temporarily used as a headquarters for the Allied Forces.

Source: 7News
The rectangular space underneath the trap door was theorised to be part of escape tunnels throughout the Brisbane CBD. Source: 7News

"He came with the intention to build up a counter attack against the Japanese forces," Major John Wright from the MacArthur Museum Brisbane told 7 News. The Museum is located inside the MacArthur Chambers.

So was the General Post Office used for an escape route?

According to Mr Wright, it is unlikely that the space was used as an escape route created by the general, however 17 "bomb shelters" from the time still exist in suburbs around Brisbane.

So what was the trap door used for? Research suggests it was "basically used for storage", Ms Roberts told the publication, however the fact that the "windows were boarded shut" and the building has "doors that lead to nowhere" remains to be a little mysterious.

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