Dublin Airport, , is an international airport serving Dublin, the capital city of Ireland. It is operated by daa. The airport is located north of Dublin in Collinstown, County Dublin. In 2015, over 25 million passengers passed through the airport making it the airport's busiest year on record. It is also the busiest of the state's airports by total passenger traffic. It also has the greatest traffic levels on the island of Ireland followed by Belfast International Airport, County Antrim.