The World Heritage-listed Port Arthur historic site in southern Tasmania is about to undergo critical structural works to strengthen its decaying buildings.
One of the island state's major tourism drawcards, the site will on Wednesday take delivery of 14 huge custom-built steel columns, the largest measuring 14 metres and weighing almost five tonnes.
The columns will form a framework to underpin the famous penitentiary ruin, which dates back to the 1840s and was once Tasmania's largest building.
The engineering project aims to strengthen the walls so the site remains safe for visitors.
Conservation works at the historic site have cost more than $7 million and should be complete by the end of 2014.