
If you want to know how to pronounce it I have (with much technical wizardry) embedded an MP3 of a rather beautiful song by a chap I was at university with called Nick Kelley. At about the 1:45 mark he manages to not only sing the word, but also make it rhyme twice. The relevant lyrics are:
I'd take the low road to keep you
From the monsters of the loch.
Would you follow me if I got in trouble
all the way to Llanfairpwllgwyngyllgogerychwyrndrobwll-
llantysilliogogogoch?
However, if you want a less artificial place name, you should pay a visit to Mamungkukumpurangkuntjunya Hill in Australia, which apparently means, Place where the Devil Urinates.
The Infernal Urinal