Purplegum,
here is how I found it. First, get to the main entrance of the Botanic Garden.
Then, look at the map of the place. Bizarrely, there are two spots on the map right in the Garden yet there is nothing on the map... how odd???
Second, when you get into the Botanic Garden from the main gate, walk straight ahead and look on the left. Can't miss it.
But if you look at the map of the Garden at the entrance, check the 2 spots with nothing... 2 blanks spots in the middle of the Botanic Garden... weird.
They are easy to find... and once you find the second station (with the outside plateforms, just walk the road (where the rails were...) and tadam.
and TZ, thanks for the tits.