The Macquarie Culvert is a double brick culvert under the original Mrs Macquarie's Road (also known as Lady Macquarie's Road[1]) in the Royal Botanic Gardens in Sydney, Australia.

[2] The culvert was probably built at the same time as the original road, between 1813 and 1816,[1] making it almost certainly the oldest bridge in Australia.

[2] The original Mrs Macquarie's Road ran from the original Government House (now the Museum of Sydney) to Yurong or Anson Point,[3][4] now known as Mrs Macquarie's Point.

[1][2] It was built on the instruction of Governor Lachlan Macquarie for the benefit of his wife Elizabeth.

[2] There is no other remaining evidence of the original road.