Ynys y Bîg is a small

private island A private island is a disconnected body of land wholly owned by a private citizen or corporation. Although this exclusivity gives the owner substantial control over the property, private islands remain under the jurisdiction of national and some ...

in the

Menai Strait The Menai Strait ( cy, Afon Menai, the "river Menai") is a narrow stretch of shallow tidal water about long, which separates the island of Anglesey from the mainland of Wales. It varies in width from from Fort Belan to Abermenai Point to from ...

attached to the island of

Anglesey Anglesey (; cy, (Ynys) Môn ) is an island off the north-west coast of Wales. It forms a principal area known as the Isle of Anglesey, that includes Holy Island across the narrow Cymyran Strait and some islets and skerries. Anglesey island ...

(in

North Wales , area_land_km2 = 6,172 , postal_code_type = Postcode , postal_code = LL, CH, SY , image_map1 = Wales North Wales locator map.svg , map_caption1 = Six principal areas of Wales common ...

) by a wooden bridge. The bridge runs from the grounds of a private house, itself also called Ynys y Bîg, preventing any public access. The bridge fell into disrepair but was reconstructed in 2019. The island lies about 1 mile north-east of the

Menai Suspension Bridge The Menai Suspension Bridge ( cy, Pont y Borth, Pont Grog y Borth) is a suspension bridge spanning the Menai Strait between the island of Anglesey and the mainland of Wales. Designed by Thomas Telford and completed in 1826, it was the world's f ...

and is part of the

Glannau Porthaethwy Glannau Porthaethwy is a designated Site of Special Scientific Interest (SSSI) along the northern shore of the Menai Strait in North Wales. It is a linear designation that extends some along the shore from Britannia Bridge in the west to Cra ...

SSSI A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of ...

. At mean low

tide Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide t ...

there is no water separating it from the mainland, whilst at high tide it is separate with an area of 0.7

acre The acre is a unit of land area used in the imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imp ...

s. It is heavily wooded and in some years

herons The herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera ''Botaurus'' and ''Ixobrychus ...

nest there in some numbers.

References

Islands of Anglesey Menai Strait Cwm Cadnant Coast of Anglesey Sites of Special Scientific Interest on Anglesey Private islands of the United Kingdom {{Anglesey-geo-stub