For many years the popular notion has persisted in Namibia that Sandwich Harbour is rapidly silting up and that soon this pristine outpost of the country's largest conservation area, the Namib-Naukluft Park, will be no more. The good news to lovers of remote, beautiful and hard-to-reach places is that one of the world's most important wetland areas for migrant Palaearctic shorebirds is not about to disappear. It has simply become even more difficult to access, which will add to its mystique as a scenically spectacular and unspoilt wilderness.

I first saw Sandwich in the late seventies, on a reconnaissance tour of the soon-to-be proclaimed Namib-Naukluft Park. Having four-wheeled up and down innumerable mountains of sand and zigzagged through many mazes of hummock-duned valleys, Sandwich was suddenly before us in all its splendour. I still experience a rush of excitement when I recall that first visual impact: an immense moving tableau of blue, green, pink and ivory. Between the shimmering Atlantic Ocean and cascading sands of towering dunes, edged by verdant reeds and rushes, was the elongated tongue-shaped lagoon, its surface pulsating with thousands of flamingos, cormorants, gulls and other birds. A lone jackal scavenged on the beach and the vast auditorium of blue sky reverberated with wind, bird flight and cries of circling gulls.

Sandwich Harbour is one of the most visibly and actively evolving geomorphic areas along the Namibian coast. It has been changing since records began and will undoubtedly continue to do so long into the future. It was once a natural harbour for whalers and fishing vessels, attracted by fresh water in the lagoon. This fossil water, possibly up to 7000 years old, seeps through from the interior at the base of the dunes. While rather brackish, it is drinkable. The salinity gradient, dictated by the levels of incoming sea water, determines the distribution of the many fish and bird species which breed there. The lagoon is protected from the ocean by a beach barrier that continuously changes shape due to the stormy Atlantic's long-shore currents and strong south-west winds. Likewise the lagoon and sandbars are ceaselessly changing.

The Sandwich wetland has two main sections. Of these the northern freshwater lagoon has shrunk considerably since the seventies, when it extended over several square kilometres. It is this that has given rise to the myth that the lagoon is silting up irrevocably and will soon disappear altogether. To the south, for about 20km2, is an expansive stretch of sand and mudflats, inundated daily by the tides. Here, the lagoon is a relatively shallow expanse of water, some 5km long and 3km wide. It is protected from the main ocean by a western sand spit that once reached the northern wetland but now joins the mainland some 3km to the south. According to Rob Simmons, ornithologist at the Ministry of Environment and Tourism and currently working on Namibia's National Biodiversity Programme, the large numbers of birds supported by the Sandwich system are gradually shifting to this southern section.

The highest recorded bird count in a coastal wetland on Africa's south-western shore was at Sandwich Harbour in 2001 - a total of 316,000 birds. Sandwich and the Walvis Bay Lagoon, 55km to the north, form the core of Southern Africa's wintering grounds for migrant shorebirds from the Palaearctic regions, supporting over 50,000 birds during the summer months and over 20,000 during winter.

In addition to the thousands of flamingos, pelicans, cormorants and other waterfowl, it is also an important breeding ground for numerous fish species, which spawn in the quiet saltwater lagoon. When Namibia became a contracting party to the Ramsar Convention on Wetlands in December 1995, Sandwich Harbour was one of the four sites listed as a Wetland of International Importance. The area is also a marine sanctuary where seals, dolphins (Bottle-nosed and Heaviside's) and even the occasional whale can be seen. Brown hyaena and Black-backed jackals are also regular visitors.

The first recorded human visitor to Sandwich was the Portuguese navigator Diego Cà£o, who sailed into the harbour in 1486 and called it Port d'Ilheo. Two centuries later the Dutch East India Company sent vessels from the Cape of Good Hope to explore Africa's south-west coast. Over the years a large number of ships sought the protection of the harbour, both to replenish their supplies of fresh water and to survey the coast for navigation charts. The French navy came in 1733, the pioneer trader Aaron de Pass in the mid-1800s, and in 1886 the South West Africa Company, attempting to find a route inland from the harbour, sent a convoy overland from Zwartbank in the Kuiseb Valley. There has been much speculation over how Sandwich Harbour acquired its name. It first appeared in 1791, on a map published by Alexander Dalrymple, a hydrographer with the British East India Company. It is thought that the natural bay might have been named after Lord Sandwich, First Lord of the Admiralty, but this theory has been discarded by some historians as Lord Sandwich relinquished his position as a government minister after Britain's loss of the American colonies in 1782. Robert Baldwin, curator of London's Greenwich Maritime Museum, suggested that the harbour acquired its name from the American ship Sandwich which visited the area in 1789.

Whatever its origin, the name Sandwich Harbour stuck (Sandvis in Afrikaans and Sandfisch Hafen in German).

The various maps and charts drawn up before 1900 invariably delineated a dotted rather than a solid shoreline, indicating that the changing morphology was already an obvious feature. It was this aspect that led to the recommendation to his superiors by Curt von Francois, commander of the German colonial Schutztruppe, that Sandwich was not suitable to be developed as a future harbour for the colony. Nevertheless until 1912 it continued to be used to export fish and guano and as an entry point for smuggling the arms and ammunition used to quell rebellious Hereros and Hottentots in the hinterland.

By this time the entrance to Sandwich was rapidly closing. An attempt was made to dynamite the sand barrier, but the fuses were soon submerged by the rising tide and attempts to revive it as a harbour were discontinued. Today all that remains of the old whaling station and the endeavours by whalers, traders, fishermen and researchers to civilise this wild place is a solitary, derelict structure surrounded by greyish-green vegetation. Earlier this year I had the good fortune to visit "what is left" of Sandwich Harbour with Bruno Nebe, whose Swakopmund-based company Turnstone Tours concentrates on high-quality guiding into spectacular and inaccessible regions of the Namib Desert. In addition to his sound knowledge of the history, climate, ecology and in particular the birdlife of the area, Bruno is also passionately involved in its long-term conservation. While I was surprised by the considerable metamorphosis of Sandwich's physical features, I left secure in the knowledge that its untamed beauty and tantalising mystique have remained intact.

Factfile

Getting There
Sandwich Harbour is about 40km south of Walvis Bay. It is notoriously difficult to access and even the most experienced desert drivers get stuck if they don't know the area. If you do decide to drive there yourself, four-wheel-drive is imperative and you will need to buy an MET permit in advance from the tourist office in Swakopmund. Seek detailed directions and local information on current conditions.
Tours
There is only one operator-Turnstone Tours-which reliably offers tours into Sandwich Harbour. The company specialises in full-day trips for a maximum of four people. Ask your African travel specialist to make your booking well in advance.