A forgotten railway

The North Shore railway has been the major form of public transport to and from the northernmost suburbs of Sydney to the city since its construction in 1890. In 1932, the southernmost 2 km section was redirected from Waverton to cross the newly opened Sydney Harbour Bridge leading to the abandonment of this short section down to Lavender Bay. For 90 years it has been used solely for storing trains for the morning peak hour.
It’s hidden in an inaccessible part of McMahons Point and most people wouldn’t know of it’s existence.
We had a family picnic today in Sawmillers Reserve, about 50m down the hill from this tunnel.