Rogerstown Estuary is an estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 in Ireland

Republic of Ireland

Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

. It is situated just north of the Donabate

Donabate

Donabate is a small suburban coastal town in Ireland, some 20 km north-northeast of Dublin City. The town is situated on a peninsula which it shares with the town of Portrane. This peninsula lies on Ireland's east coast, between the Rogerstown Estuary to the north and Broadmeadow Estuary to...

-Portrane

Portrane

Portrane or Portraine ) is a small seaside town one kilometre from, and merging into the larger town of Donabate in Fingal, north County Dublin, Ireland.- St. Ita's Hospital :...

 peninsula, and also south of Rush

Rush, Dublin

Rush is a small seaside town, with a population of 8,280, situated between the communities of Skerries and Lusk in Fingal, Ireland. There has been a large population increase since the previous census in 2002, comprising mostly people from north Dublin....

, on Ireland's east coast about 25 km (15.5 mi) north of Dublin.

The estuary is made up of saltwater marshes, raised salt marsh, wet meadows and riverine shallows and creeks. It covers an area of 3.63 km² (897 acre), and is divided by a causeway and bridge built in the 1840s to carry the main Dublin–Belfast

Belfast

Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...

 railway line. It is internationally recognised as one of the most important east coast sites and is vital for wintering wildfowl and waders and birds on passage. Birds come to the estuary from the Arctic

Arctic

The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

.

The estuary's mouth separates the beaches of Donabate and Rush; and the mouth is so narrow, it is theorized that a person would be able to cross from Rush to Donabate, at gradual walking pace, within a timespan of less than a minute, if there was no water. According to local legend

Legend

A legend is a narrative of human actions that are perceived both by teller and listeners to take place within human history and to possess certain qualities that give the tale verisimilitude...

, there was once a bridge across the mouth, however, it was dismantled after various suicide

Suicide

Suicide is the act of intentionally causing one's own death. Suicide is often committed out of despair or attributed to some underlying mental disorder, such as depression, bipolar disorder, schizophrenia, alcoholism, or drug abuse...

s. An apparent remain of this bridge still exists today, on the Donabate beach.