Stonemasons from Sydney's historic Rookwood Cemetery have spent the past two days rebuilding 14 broken headstones at Wollongong Cemetery which mark the final resting place of the Illawarra's early pioneers.

Almost 100 graves dating from the 1800s were damaged in January last year, when vandals pushed over marble headstones, causing them to shatter and leaving tombstones exposed.

Urns and vases were smashed and one vandal carved the name "Calum" into a piece of marble.

Wollongong Cemetery historian Carol Herben welcomed the conservation work, which was funded by Rookwood's General Cemeteries Trust.

"I think it's marvellous - part of our heritage and history lies in this cemetery with the pioneers who established this city," she said.

"(The graves will be) restored with minor damage from the vandalism, but they're the best they could possibly be instead of lying in pieces of rubble."

The stonemasons have followed traditional conservation techniques whereby pieces of stone are painstakingly pinned rather than glued together.

The most complex repair involved a marble headstone which had shattered into 11 fragments.

Stonemason Helmut Mutschall said it was a pleasure to restore the historic graves.

"These days (gravestones are) all square and granite, 99 per cent of them are carved by machines in China," he said.

"The craftsmanship (of the old graves) is unbelievable, they're chiselled and carved by hand, so we're trying to restore them to the original condition with original materials. It's satisfying to see it back together again and not crumbling into dust."

Ms Herben said she hoped funds to repair the remaining graves would soon be forthcoming.

In December Wollongong City Council erected a $300,000 security fence around the cemetery.