Flying into Auckland on a clear day you will immediately be struck by the numerous islands off the eastern coast of the North Island. This is the Hauraki Gulf, an area of some 4000 square kilometers. It is the boating playground for Aucklanders and one of the best boating areas in the country.

Read more: Auckland: New Zealand's Gateway City

Despite its large size, the Gulf is very sheltered from all but extreme northerly weather.

It is protected by the mainland on the west and south and the Coromandel Peninsula to the east. Two islands, Great Barrier and Little Barrier, offer some protection from the north. It provides the entry way for Auckland's port and eastern harbor, the Waitemata Harbor.

Read more: Best Coromandel Beaches

The Gulf is also teeming with marine life, including dolphins, penguins and even whales.

If you are spending any time at all in Auckland, a visit to one or more of the islands or a harbor cruise is highly recommended. Some of the islands are populated while others are maintained as reserves or private land. The best way to explore all of the islands is by private boat, but several are serviced regularly by ferries.

Book now: Auckland's Whale and Dolphin Safari Cruise

The main islands are as follows:

Rangitoto Island

This is the most distinctive island in the Gulf and also the youngest. It was formed as the result of a volcanic eruption only around 600 years ago. Uninhabited, it has numerous walking tracks around the island and to the volcano summit.

Motutapu Island

This is virtually joined to Rangitoto, but is completely different in landscape. It is mainly farmland, with many pretty bays on its coastline.

Rakino Island

This is a small island to the north east of Motutapu. It is surrounded by lovely beaches and has a very small resident population. However there are no shops on the island so it remains off the tourist route - just how the inhabitants like it!

Motuihe Island

This small island, which sits across the channel from Rangitoto and Motutapu is a recreation reserve and is a very popular spot for picnickers in the summer. It has two beautiful beaches, separated by a thin strip of land, which provide shelter from whichever wind is blowing.

Waiheke Island

This is the largest island in the inner Gulf. It has a significant permanent population and is essentially a suburb of Auckland City, with many people commuting daily. With superb beaches, cafes and vineyards, this is a popular place for visitors.

Read more: Vineyards of Auckland

Pakatoa Island

One of the few privately owned islands in the Hauraki Gulf, Pakatoa lies at the eastern end of Waiheke.

Rotoroa Island

Rotoroa is close to Pakatoa and recently was gifted to the city of Auckland in 2010. There are plans to make the island more available to the public.

Ponui Island

This, with Pakatoa and Rotoroa, completes the group of three islands to the southeast of Waiheke. Most of the island is privately farmed, although it is also used by camping groups such as the scouts on a regular basis.

Browns Island

This small island is the first to be passed on the ferry trip from Auckland to Waiheke or Rangitoto. Like Rangitoto, the island is a volcano and is uninhabited. Due to its closeness to the mainland it is often visited by small boats and jetskis. However it is difficult to land on the island in a larger boat due to a lack of suitable anchorages.

Tititiri Matangi Island

Known as "Tiri Island", this lies off the end of the Whangaparaoa Peninsula to the north of Auckland. It is a nature reserve, notable for the rare native bird the takahe. It is accessible to the public and a regular ferry service provides a great day trip.

Kawau Island

Some 25 miles (40 kilometers) north of Auckland and close to the mainland, Kawau is another popular tourist destination for the historic Mansion House. There are also a few private homes on the island, most of them only accessible from the sea.

Little Barrier Island

This lies some 50 miles north of Auckland. It is one of the most important wildlife sanctuaries in New Zealand and as such access is not permitted. It is home to many species of endangered native plants and birds.

Great Barrier Island

Great Barrier is the largest island in the Hauraki Gulf and the fourth largest island in New Zealand. Along with Little Barrier it was given its name by Captain Cook in 1769. It is an apt description because it provides extensive shelter for the entire Hauraki Gulf from the Pacific Ocean.

It is also the island furthest from Auckland, being 62 miles (100 kilometers) from the city center. It has a population of less than 1000 and no electricity, so it attracts a hardy and 'alternative lifestyle' set. However, it remoteness and many beautiful beaches make it a memorable place to visit.