Alderney’s longest beach extends for around half a mile along the island’s south-east coast. Its broad, gently sloping sand is popular for swimming, paddling, kayaking, beach games and rockpooling, with a particularly extensive lower shore exposed as the tide falls.
These predictions use Braye Harbour, the Alderney reference location used by this service. Tide times and water levels at Longis Bay may differ from the prediction because of the local shoreline, weather, waves and atmospheric pressure. Times are shown in local Alderney time.
From 1 June to 15 September, dogs are allowed on Longis Beach only between 5pm and 8am.
This evening and early-morning access is being introduced on a trial basis for 2026 and 2027. Dogs are not permitted on the beach between 8am and 5pm during those dates.
Longis Bay stretches for around half a mile along Alderney’s south-east coast, forming the island’s longest sandy beach. Its broad, gentle slope makes it popular for swimming, paddling, kayaking and beach games when conditions are suitable.
The large curving anti-tank wall behind the beach was built on the dunes by forced labour under the German occupying forces during the Second World War. Intended to obstruct an Allied landing, the six-metre-high structure now forms one of Longis Bay’s most prominent landmarks and provides some shelter from the wind. Observe any signs and barriers around the historic defences and do not climb on unstable structures.
At the western end stands the Nunnery, a historic fortified site incorporating the remains of a late Roman fort dating from around the fourth century. A principal visitor access point is nearby, with a car park and public toilets behind the site. A sloping route leads towards the upper beach, but movement beyond it is over natural sand whose firmness varies with location and tide.
Longis is one of Alderney’s recommended locations for rockpooling and beachcombing. Begin exploring at least an hour before low tide and keep checking the returning water; wear footwear suitable for wet rocks, replace any stones you lift and leave marine life where you find it. Gobies, prawns, sea anemones and crabs may be found in the pools.
The beach forms part of the wider Longis Nature Reserve, whose habitats include intertidal shore, species-rich grassland, freshwater pools, reedbeds and coastal heath, all managed by the Alderney Wildlife Trust. A small herd of Guernsey cattle is used to maintain more than 20 hectares of wildflower-rich grassland. Within the reserve, give grazing animals space, keep dogs under effective control and use established paths where requested.
There are no lifeguards on Alderney’s beaches. Longis is popular for swimming because of its gentle gradient, but it remains an open coastal beach and conditions vary with wind, waves and tide. Stay within the bay and do not swim beyond the headlands, where you may encounter Alderney’s powerful offshore currents; swim with another person where possible, supervise children closely, and choose the greater shelter of Braye during rough weather.
Longis changes considerably through the tide because of its broad, gently sloping shore.
Around higher water, more of the lower beach is covered and the water is closer to the upper shore and main access points. Less sand is exposed, but the walk from the Nunnery-end access to the water is shorter.
As the tide falls, a broad expanse of wet sand appears across the bay. The shallow gradient allows the water to retreat a considerable distance, giving much more room for walking and beach games and exposing the rocks and pools around the shore.
At lower tide, the water may be a considerable distance from the upper beach. Check the tide direction before entering the sea and allow enough time for the walk back to the main access. The anti-tank wall provides some shelter on land, but it does not protect the bay from every wind or sea direction, and actual water levels may differ from predictions because of atmospheric pressure, wind and waves.
Explore Alderney’s tide times, harbour information and island guide, including its other beaches and local advice.
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Tides. Tide predictions are forecasts. Actual sea level is affected by atmospheric pressure, wind and waves. Always observe the sea and your surroundings.
Swimming. Sea swimming carries risks: currents, waves, rocks, submerged structures, boats and cold water. This page is for planning and does not confirm conditions are safe. Do not assume the beach is lifeguarded.
Facilities. Facilities and café opening hours change seasonally. Check directly before making a journey specifically to use them.
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