Taking its name from the Tropic of Capricorn, which cuts through it, this stretch of the Queensland coast is the southernmost part of the Great Barrier Reef. It is here that you will find the most spectacular of the Great Barrier Reef islands, Heron Island, off the coast from Gladstone. Herons reefs are a source of enchantment for divers and snorkelers; its waters boast 21 dive sites. In summer, large turtles lumber ashore to nest on its beaches, and in winter humpback whales cruise by.

To the south of Gladstone, off the small town of Bundaberg, is another tiny coral cay, Lady Elliot Island, a nesting site for tens of thousands of seabirds and home to a first-rate fringing reef. Two little-known attractions in Bundaberg are its good shore scuba diving and a loggerhead turtle rookery that is a major drawcard in summer.

Gladstone: Gateway to Heron Island

Gladstone: 550 km (341 miles) N of Brisbane; 1,162 km (720 miles) S of Cairns

The industrial port town of Gladstone is the departure point for beautiful Heron Island. Gladstone is on the coast 21km (13 miles) off the Bruce Highway. Most flights to Gladstone arrive in time to connect with the ferry to Heron Island, but if you need to stay overnight a couple of good, centrally located options are Mercure Gladstone (  tel. 07/4979 8200; www.accorhotels.com.au) and Rydges Gladstone (  tel. 07/4970 0000; www.rydges.com).

Heron Island

72 km (45 miles) NE of Gladstone

Heron Island is often referred to as the jewel of the Reef.And rightly so. The difference between Heron and other islands is that once there, you are right on the Reef. Step off the beach and you enter magnificent fields of coral that seem to stretch for miles. And the myriad life forms that abound here are accessible to everyone through diving, snorkeling, or reef walks at low tide.

There has been a resort on Heron since 1932, and in 1943 the island became a national park. It is a haven for wildlife and people, and an experience of a lifetime is almost guaranteed at any time of year, particularly if you love turtlesHeron is a haven for giant green and loggerhead turtles. Resort guests gather on the beach from late November to February to watch the female turtles lay eggs, and from February to mid-April to see the hatched babies scuttle down the sand to the water. Every night during the season, volunteer guides from the islands University of Queensland research station tag and measure the turtles before they return to the water. Only one in 5,000 hatchlings will live to return in about 50 years to lay its own eggs. Humpback whales also pass through from June through September.

Three days on Heron will give you plenty of time. The island is so small that you can walk around it at a leisurely pace in about half an hour. One of the first things to do is to take advantage of the organized activities that operate several times a day and are designed so guests can plan their own days. Snorkeling and reef walking are major occupations for visitorsif theyre not diving, that is. The island is home to 21 of the worlds most stunning dive sites.

Guided walks provide another way to explore the island. Walks include a visit to the islands research station. As for the reef walk, just borrow a pair of sand shoes, a balance pole, and a viewing bucket, and head off with a guide at low tide. The walk can take up to 90 minutes.

Heron is also home to colonies of mutton birds; be warned, they can be particularly noisy during their breeding and mating season, from November to January. They also create a fairly . . . shall I saydistinctive smell (you get used to it, but some people find it highly offensive). Thats nature for you.