Wood monuments
Here in New Zealand most boundaries are marked with wooden pegs.
Originally of Totara, a native tree that is very ground hardy. I've found some that are more than 100 years old.
These days they are usually treated pine.
There have been some attempts to use plastic pegs - which are proving unpopular. And there are some marked metal disks - usually in urban areas.
We use pipes or rods - called tubes and spikes here - without caps - for traversing.
Wood monuments
> Here in New Zealand most boundaries are marked with wooden pegs.
>
> Originally of Totara, a native tree that is very ground hardy. I've found some that are more than 100 years old.
Richard Abbott has mentioned that jarra wood (if I recall correctly), a rot-resistant species, was widely used in the past for pegs in Australia.
I once did a small survey of a parcel for a US embassy in Georgetown, Guyana, a very tropical setting with lots of rain. I was surprised to learn that wood pegs (actually "paals", as they were called following the much earlier Dutch usage) were also commonly used there. There was a species of dense, rot-resistant hardwood, greenheart, that was used.
Wood monuments
After some 2 months of searches and traverse closures for a development in rural residential rain forest, original evidence of several section and 1/4 cors was yet to be found. Cooperative analysis of 2 private firms as well as field searches was involved.
I took the ferry on a Saturday morning to the island involve and found shards of cedar of one original post some 2 feet deep, and the post itself at another corner under heavy moss, with the hole it fell from at a the base.
100 year old posts are still out there if you know where to look and can see things others would never notice, particularly if you have good theory on possible search locations from deep analysis of the GLO history.