Anywhere symilar to this in New Zealand?

[Coldrider]

not to mention the "tank traps" on some of the tracks,or is that an urban myth

Desert Storm has claimed a few.

[FJRider]

not to mention the "tank traps" on some of the tracks,or is that an urban myth

No tank "traps" .. just the likelyhood of tanks or trucks. They take right of way.

[unstuck]

Central Otago.

[pouakai]

Done it once I think is amazing but can only ride on tarmac right? As far I know there is no tracks you can ride off road because it's all Army base around it?

Not quite:
http://www.offlimits.co.nz/tussock-buster

Did their weekend at Tekapo - was awesome, especially a guided 100k trail - flat out !

P

[FJRider]

Central Otago.

That's just around the corner from my place ...