Dublin metro system

There is no metro system, as in underground railways.

This is a map of the transport system (except buses)- https://www.dublinpublictransport.ie/dublin-train-map

The red and light green lines are LUAS- the trams.

The dark green line is the DART- which are frequent suburban trains.

The other lines are Dublin local lines of Irish Rail.

There is also a very dense network of bus services- I'm not aware of a map of them.

Generally a tourist can get to most places using walking, LUAS and parts of the DART. It is pretty unlikely you will be using much if any of the Irish rail network.

If you buy a Visitor Leap Card either at the airport on arrival or on line (delivered by mail)- https://about.leapcard.ie/leap-visitor-card

you can use all modes of transport. Don't worry about the 'Short Hop' Zone- you won't be going outside that zone. For Commuters from outside the city there are also Medium Hop and Long Hop Zones.

Coming from the airport it is only valid on Dublin Bus routes (yellow and blue routes), but they are frequent and fast. It is not valid on the various private companies routes.

On the Dublin Public Transport website above note the journey planner.

I like the city mapper app and website.

https://citymapper.com/dublin?lang=en

Just enter your start and end destination and it will give you multiple options—metro/tram/train, bus, walk, drive.

I’ve been playing around with it today trying to see which hotels are close to the Rabbie’s tour departure point. It’s pretty helpful. I used it in Lisbon when the trains were canceled, and I had to return via bus.

If you've seen coverage of the Dublin Metro online, it's because they're still arguing about building one. There have been various schemes on and off over the last few years which have fallen through because of economic difficulties and changes in which party is in control of the government.