The Royal Botanic Garden, Sydney

Sydney's Botanic Garden was laid out on Farm Cove in 1816, on ground where the colony had already failed to grow wheat — which makes it the oldest scientific institution in Australia and its oldest botanic garden. Look for what a Victorian garden was for: gates, urn-lined paths, an equestrian statue, a carriageway, people at leisure on a Sunday.

Then there is the building that is not there any more. In 1879 the Garden Palace was thrown up on the garden's Macquarie Street edge in eight months — a vast timber-and-glass hall designed by Colonial Architect James Barnet for the Sydney International Exhibition, which opened on 17 September. Its dome was the largest thing on the skyline and appears above the pond the way a cathedral appears above a town.

It stood for three years. Fire broke out at about twenty to six on the morning of 22 September 1882 and it burned fast enough that the windows of the Macquarie Street terraces cracked in the heat. An official enquiry never established how it started. Government departments had been storing records inside, so the fire also took the early land and squatting records of New South Wales, and an irreplaceable collection of Aboriginal artefacts. The burning survives here as a lithograph rather than a photograph. What is left today is the gates, the garden, and an outline in the grass.

One monument is worth knowing about before you look at it. The obelisk standing in the pond was raised in 1844 by the friends of Allan Cunningham, who collected for Kew across Australia and New Zealand and came back in 1837 to run this garden as Colonial Botanist — a job he gave up inside a year, and outlived by barely another. It was a memorial and nothing more: he lay across town in the Devonshire Street cemetery. That changed in 1901, when the cemetery was cleared to build Central Railway Station and his remains were brought back and sealed inside the obelisk behind its marble plaque. In the 1870s photograph of the obelisk, it is still empty.