The wood is from two species native to NZ (pohutukawa and teatree), most of the big bits were cut off an old pohutukawa that had slipped down a bank onto the tidal flats, so its drift wood that hasn't actually drifted anywhere. The piece on the far left is a teatree stump I dug out of a swampy spot on my fiancees parents property, they make great pieces but are a lot of hard work!
The sand is just "builders sand" from the local hardware store (Bunnings. I'm guessing by the car in your avatar you're from Australia, its Cemix brand, not sure if they stock it there).
Thanks. It nearly is, its missing one barbell, they were damaged when I got it and it crashed into the rough background a couple of times while it was settling in which messed them up pretty badly. One has grown back well, the other is much slower and I'm starting to wonder if it will grow back at all.