The IronMan 70.3 world championship event taking place in and around Dublin on Sunday will involve significant road closures and local access restrictions.

The Sandymount, Blackrock and Sandycove residential areas will be particularly affected.

Locations including the city centre quays will be closed at different times in the morning on August 9th as 2,500 athletes compete.

The event includes a 1.9km swim in Scotman's Bay, Dún Laoghaire, with athletes divided into groups for the start, followed by a 90km cycle and ending in the Phoenix Park, where competitors finish with a 21km run.

Between 5am and 10am, no vehicles will be able to access Blackrock. From 4am to 9.30am Dún Laoghaire harbour will be closed. The town itself will be unaffected.

“The swim starts from Sandycove, with closed roads all around this area,” the organisers said.

"The transition from swim to bike takes place on the green at Marine Parade. We would suggest local swimmers use the Forty Foot to enter the water between 6am and 9am as the Sandycove area will be very busy with 2,500 athletes entering the water."

After the swim, cyclists will travel from Dún Laoghaire, over the East Link bridge and down the north quays, between 7am and 10.30am.

Traffic exiting the Port Tunnel will be unable to cross the East Link bridge until after 10.15am and there will be no access to the north quays.

In Sandymount, there will be no access to either Strand Road or Beach Road between 6am and 10am.

A detailed breakdown of all disruption and access restrictions on Sunday morning can be found at eu.ironman.com.