This was a physically very demanding day a visit to the Minh Dam caves in the Long Hai Hills. These caves, some several hundred metres into the heart of the mountains, served as the Vietcong's local head quarters throughout the Australian's presence at their Nui Dat. They survived both carpet bombing from the air and search and destroy missions on the ground to present a constant threat to Australians ground forces, especially after the creation of the Barrier Minefield.
The more active members of the group squeezed, crawled and climbed their way through gaps between rocks and boulders to reach what was once the impenetrable inner sanctum of the Vietcong with its own kitchen, medical centre, offices, sleeping quarters and radio communications room.
The memorial outside the entrance to the first caves was of particular significance - the dates on it 1966-72 reflected precisely the time Australian troops were based at nearby Nui Dat. Aussie patrols found plenty of other caves and bunkers in these hills, cleared them and destroyed them - but the Minh Dam caves were never located and remained intact throughout.
Sandy told us of how his brother Chris was involved in the rescue operation after the Black Saturday disaster In 1970 which took place on the other side of the Long Hai mountains, claiming the lives of nine Australian soldiers and injuring another 26. It and was the last time Aussie troops went into the mountains to seek out the enemy.
Apropriately, the next stop was the Horseshoe - the former Fire Suport Base where Barrier Minefield began its 11 km march to the coast. The Barrier minefield was the source of many of the booby-trap land mined 'recycled' for use against Allied troops in incidents like Black Saturday.
We climbed the distinctively shaped hill, which is mostly a gravel quarry now and looked down the line the minefield would have taken as more than 23,000 M16 Jumping Jack mines were planted, only for 3000 to be lifted and used against the Allies.
We returned to Tommy 3 for lunch via the site of the Ba Ria bridge and the War Heroes Cemetary in Barie (with little solar pwered lams on the cgarves that come on at night).
At Tommy 3 we watch a video about the minefield and the deadly consequences of this tactical error that our book - and many other sources - claim is Australia's greatest military blunder since Gallipoli.
Free time in Vung Tau - a delightful town in itself with three popular beaches - was followed by dinner at the Bamboo restaurant which brought a long day and physically challenging day to a pleasant close.