Five hundred million years ago, the Jersey landscape was buried under a towering mountain range that extended through northwest France.
Shale and volcanic rock, including Jersey's peculiarly pink granite, account for around 90% of its area. This granite has been used in building many of its farmhouses and public buildings, and forms about a third of the Island.
Over the course of geological history, sea levels have risen and fallen. Some 18,000 years ago, a vast ice sheet lay 200 miles north of Jersey and the sea level was 100 metres lower than it is today. At that time, the Channel Islands lay on a bare tundra wasteland and Palaeolithic hunters followed herds of animals across Europe.
The present perimeter of the Island only began to take shape about 10,000 years ago, when rising sea levels severed the last vestiges of land connecting southeast Jersey and France.
The topography of the Island is quite straightforward, with the highest points and rockiest shorelines located in the north. By and large, Jersey can be described as a plateau etched by parallel and wooded gullies and ravines that flow to the sandy shores to the south.
Intertidal Zone
Exploring Jersey's rich and varied coastal environments is one of the most enjoyable and rewarding experiences you can have when you visit. However, it is important that you are aware of Jersey's tides; their size & strength, times and heights.
Jersey's tide rises and falls twice each day, and Jersey almost doubles in size such is the range of the tides around our coast. In comparison, the tides in mainland UK might range from between 0.5 - 2.0 metres. In Jersey, our tidal range is more like 3.5 - 12 metres, a dramatic difference and something that most people are not familiar with.
The video on this page was produced by local resident Annette Lowe in partnership with the Jersey Lifeguard Service and features Andrew Syvret, a marine ecologist and local expert on one of Jersey's most popular areas for low-water walking. Whilst this video focusses on Jersey's south-west coast, where Seymour Tower (a popular, historic landmark) stands a mile or so offshore from the La Rocque headland at the southern end of Grouville Bay, it provides general, common-sense advice for respecting the sea.
Seymour Tower is iconic not just for its offshore location. It stands amongst a strange, complex coastline of low-lying reefs and rocks extending westwards to St Helier's doorstep, a lunar-like seascape that could well be the biggest rock pool in the world. It is made doubly unearthly by the fact that this vast reef system disappears beneath the Atlantic Ocean twice daily a consequence of Jersey's massive tides, at 40ft/12m some of the highest in the world. Its importance is reflected in its status as an internationally recognised Ramsar wetland site.
North coast
The north coast is the wildest part of Jersey. The steep heather and bracken-clad cliffs have many caves, some accessible only by boat. These same cliffs provide a dramatic backdrop to some of the Island's most beautiful bays, including Grève de Lecq, Bonne Nuit, Bouley Bay and Rozel.
On either side of Bouley Bay are two forts, Leicester and L'Etacquerel, built to keep out the French. The latter was used to house the British garrison during the Napoleonic Wars. Further east is the Dolmen du Faldouet, an unusual grave.
West coast
The magnificent sandy expanse of St Ouen's Bay dominates the western coastline. The area known as Les Mielles encompasses the shoreline, and the flat, marshy land behind these dunes provides a number of habitats for plants and animals. So do the rocky outcrops at either end of the bay, where the rockpools and shallows teem with life.
The dunes to the south, Les Blanches Banques, are home to a wide variety of flowers and have been designated as a Site of Special Interest. St Ouen's Pond, surrounded by marshy land and thick reed beds, is Jersey's largest natural expanse of fresh water, while rough grazing land, small cultivated fields and the escarpment only add to the region's diversity.
South coast
Jersey's southern coast has four main sub-regions. They are:
- St Brelade's Bay, a beach of golden sand protected from most winds.
- The town area of St Helier.
- To the west of St Helier, the sweeping expanse of St Aubin's Bay.
- The low-lying farming area surrounding St Clement's Bay.
East coast
This coastline faces Normandy and comprises the Royal Bay of Grouville and St Catherine's Bay. Mont Orgueil (Gorey Castle) dominates the skyline, and its strategic position indicates that there were fortifications on this site long before the existing castle was built in 1204.
Also to be found in the area is La Hougue Bie, one of the finest prehistoric sites in Europe. This massive burial mound serves as evidence that the Island has been inhabited for thousands of years.
The Interior
The interior of the Island is a mixture of woodland, intensely-farmed arable land and mineral-rich grazing land. The latter provides the pasture for the herds of Jersey cows, and is also what gives Jersey's other famous export - the Jersey Royal - its special flavour.
Most fields are small and bordered by granite walls or hedgerows. And all over the Island you'll notice steep, south-facing slopes, or côtils, where early potatoes and other crops are cultivated.
Woodland is mainly located in deep valleys, eroded by fast-flowing streams. In the early morning the blended notes of many songbirds echo through the glades and dells. In the summer, broad canopies of oak, ash, wild cherry and sycamore shelter the thriving population of red squirrels and are home to a rich array of other mammals, birds, flowers and shrubs.