North Bull Island

Bull Island is a geological accident. The North Bull Wall was built across Dublin Bay in the early nineteenth century, on advice from Captain William Bligh among others, to scour a channel and stop the port silting up. It worked, and the sand it displaced began piling behind it. Within decades an island had formed where there had been open water, and it is still growing. That new ground now carries dunes, salt marsh and mudflat, and it is a UNESCO biosphere reserve - the only one within a capital city - supporting thousands of overwintering waders and geese, including Brent geese that arrive from Arctic Canada. Dollymount Strand along its seaward side is a five-kilometre beach used by Dublin for walking, kite surfing and, historically, driving on the sand. Two golf courses occupy part of the island, which sits oddly with the conservation designation and is a long-standing local argument.

What you actually see

• The made island - ground that did not exist before about 1800.
• The overwintering birds - waders and Brent geese from Arctic Canada.
• Dollymount Strand - five kilometres of beach on the seaward side.
• The dune and marsh systems - still building as the island grows.

When to go

October to March for the bird numbers, which are the point of the reserve. May to September for the beach. Tides matter - the mudflats and the birds on them are only there at low water.

Honest expectations

Dogs off lead and vehicles on the strand disturb the birds, and enforcement is patchy. The golf courses take up a large share of the island. It is a city beach - litter after warm weekends is a persistent problem.

Nearby

Clontarf and Dublin city are west; Howth is north across the bay.