The iconic green DART commuter trains carry around 80,000 passengers every day as they traverse the city and hug the coastline from Greystones in the South to Malahide or Howth in the north. Trains run from c.06:30 - 23:00 - check www.irishrail.ie/your_journey/timetables.asp to avoid disappointment/frustration. Trains operate every 5/10mins during peak times, and there's an average gap of 20mins during off-peak and 20-30mins on Sundays and Bank Holidays. Make like a local and buy pre-paid tickets to bag yourself a canny discount.