How to Find Cheap Fares -- Like the One I Just Found
 

I was thinking about going to Barcelona (as part of a work trip to N. Ireland) and I found a ridiculously low fare: $210 (basic economy); $255 (main cabin) one-way from Kauai to Barcelona on United, with only one stop! That fare is only available one particular day, which luckily, happens to work for me.

But my question is how do you find out about these kinds of fares? I found this by chance. I'd love to know if there are similar fares to other European cities around that same date -- or for my return. Do you have to check every city? Is there an APP that lists extra low fares?

I'm hoping to find a similar low fare for my return from Dublin--or from another airport that it would be easy and inexpensive to fly to. (Prices to fly back from Belfast are much higher, and it's an easy bus ride to the Dublin airport.)

Thanks for your help!

Start here: https://www.flyertalk.com/forum/mileage-run-deals-372/

And here: https://matrix.itasoftware.com

Gardyloo: Thanks SO much. You've got major cred since your Japan recommendation! ;-)