The lighthouse at Cape Reinga is at the very top of NZ. If you're a more adventurous hiker, there are a number of longer walks you can do to the lighthouse. Otherwise, you can drive there. Check out the options at the website we've linked.
Walk up a dormant volcano. You can take a ferry from downtown Auckland to get out to Rangitoto. Note: you will need to pack water and lunch/snacks, as there are no cafes etc on Rangitoto. Also, there are limited ferries per day, so check when the last one leaves from Rangitoto (Matt almost got stuck out there one day).
Waiheke Island is known for its great wineries, our favourites are Mudbrick, Stonyridge and Casita Miro. Take a ferry from downtown Auckland out to Waiheke for a day of winery hopping. There are taxis and buses to get you around the island. You can also join a wine tour if that's more up your alley. Note: check when the last ferry of the day leaves from Waiheke, as it's the only way back to Auckland. If you miss it, you're stuck there for the night. If you are travelling with kids, there are also a lot of beaches and various other activities on Waiheke that are more child friendly.
One of the most beautiful beaches in NZ (it's actually been voted as one of the world's top 10 beaches!). There is a small hike/walk to get there from Whangapoua beach. There are no shops, bathrooms etc on the beach, it is completely secluded. A lovely spot for some tanning, swimming and a picnic.
Abel Tasman National Park is located close to Nelson (also a great spot for wineries). There are a number of hikes you can do through Abel Tasman ranging from short hikes (a couple of hours) to longer hikes (over a few days - you would need to book in for those). The National Park is surrounded by stunning beaches. You can also go kayaking through here - plenty to do!
A few notables include: AJ Hackett Bungy, Gibbston Valley wineries (there are so many - pick a few and spend the day tasting various wines), hike around Lake Hayes, enjoy a degustation meal at Amisfield, luging (great for kids too), jet boating, visit Arrowtown, mountain biking, the list goes on. Let us know if you want to head here and we can give you some more recs!!
If you are going to extend your trip to 10 days or more, we would definitely recommend getting down to the South Island. One place that is a little harder to reach, but totally worth the trip, is the Milford Sound. You can stay in Te Anau and drive over to Milford Sound for the day to do a boat tour. The views are breathtaking!
Our amazing friend Em, aka @forkingyum, curated a list of Auckland's top eats. Be sure to check some out and let us know what you thought! Breakfast: - Best Ugly Bagels - Ozone - Cazador Deli - Honey Bones - Bestie - William's Eatery - Rosie - Odettes - Orphan's Kitchen - Daily Bread - Amano - Cornwall Park Cafe - Kohi Cafe - St Helier's Bay Cafe - La Voie Française Lunch: - Little and Friday - Ripe Deli - Mr Taco - Little Bird Unbakery - Catroux - Ralph's (burgers) - Sip Kitchen - Coffee Pen Restaurants: New Zealand / Bistro: - Ahi - Mr Morris - Depot - Onslow - Saxon & Parole - Soul Italian: - Ada - Amano - Lilian - Pici - Pasta e Cuore - Andiamo - Prego - Non Solo Pizza - UMU Bars (with great food too): - Hotel Ponsonby - Clay - East Street - Bar Celeste - Apero - Peach Pit Japanese: - Masu - Omni - Azabu - Ebisu Korean: - Goshu - Ockhee Thai: - Saan - Kiss Kiss Indian: - Oh Calcutta - Cassia - Mr Spicer - Satya Chai Lounge Turkish / Greek: - Gemmayze Street - Daphnes