The cache is not at the posted coordinates.

Covering 5.5. hectares, the Norfolk Island Botanic Garden boasts a unique collection of plants endemic to Norfolk Island.
The original garden was owned by Mrs Pat Moore and covered 0.6 hectares. Mrs Moore (nee Annie Eliza Kirkpatrick) moved to Norfolk Island from New Zealand in 1949. She purchased the property and planted numerous species of plants found only on Norfolk Island, starting the collection that became the basis for the Norfolk Island Botanic Garden.
In 1986 the Norfolk Island Botanic Garden was declared a part of the new Norfolk Island National Park.
The garden displays a collection of Norfolk Island’s unique flora and has a strong emphasis on increasing knowledge, appreciation, and enjoyment of Australia’s plant heritage.
The Norfolk Island Botanic Garden also houses the Discovery Centre, where visitors can learn more about the incredible plants and animals found in the Norfolk Island group.
To obtain the coordinates you need to complete the Norfolk Island Botanic Garden Adventure Lab.
You will find the cache at S29 01.ABC E167 56.DEE