Llanfairpwllgwyngyllgogerchwyrndrobwllllantysiliogogogoch (or Llanfairpwllgwyngyll, for short) is a small town on the Isle of Anglesey in North Wales. It's on the road to Holyhead, where ferries connect to Ireland.
It is the longest place name in Europe, and one of the longest in the world.
According to Wikipedia, Llanfair Pwllgwyngyll was the original name. It was changed as a publicity stunt in the 19th century to Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch
nothing, it's not a word.
I think you mean the longest place name in Wales, UK.
See the related link below.
Llanfairpwllgwyngyllgogerchwyrndrobwllllantysiliogogogoch is in North Wales on the Isle of Anglesey just over from the mainland, and it is a railway station.