Wellington Zoo - 50% off General Admission (Child - $5.25 / Adult - $10.50)

Have been a few times, it's quite cool to visit on a nice day.

They rarely have gold coin entry, but the lines are massive, so for half price, without the lines, isn't too bad.

Some conditions:

Valid from Oct 24, 2014 to Dec 31, 2014. Limit: 100 for you and 100 gifts for others.
Child 3-14 years. Under 3s free. Under 14s must be accompanied by an adult. No exchanges. No refunds or cash back (except where required by law). Must be used in 1 visit. Not for use with other offers.