
On the road between Drury and Pukekohe is a Dead End Road called SIMS Road. It's on the left coming from Drury just before the start of the second over taking lane. If you get to the gas station, golf course and Glenbrook intersection you've gon about 2km too far.
It is only about 1km long but is a sure Mud run after a rain storm.
It is not a "No Exit" as the sign says. It connects up to Sims Road on the other side of the Railway Lines via a small (but good) bridge.

Also try the beach out at Kariotahi. Nice to get down to the Waikato Heads.
Tread lightly, keep away from the untouched dunes and be aware of the other beach users.
Get to it via Waiuku.

There are a few tracks in the maramarua forest. But the most fun Mud Run was the old Meremere Cable Way. Now closed.
When the mud dried you could peel it off like plastic!
Very straight but massive potholes next to where each of the pylons used to be. And I mean MASSIVE ute swallowers!

Klondyke Road out at Onewhero has nice views looking down at Port Waikato. It eventually drops down to the port. Get there from Tuakau, take the road south out of town, over the river and take the second turning on the right.
Follow this road up the hill for about 10-15 min until your on the other side of Onewhero.
The turn for Klondyke Road is on the road to Wairamarama that you will find yourself on after travelling through Onewhero. About 1 to 2km south out of Onewhero on the Right.
Note: there are 3 roads that drop down to the Port Waikato Road, Klondyke is the 3rd.