|By Akke at en.wikipedia [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], from Wikimedia Commons|
With the aqueduct at Pontcysyllte
English bargees get put out of kilter
Cos they can't say it proper;
They just come a cropper.
rndrobwllllantysiliogogogoch's undoubtedly tougher.
(as an anglophone who tries to pronounce welsh words properly, I suggest you pronounce the 'll' in the same way that you would say the 'tl' sound in 'Bentley' (though this is no help if you use glottal stops), and the whole word as something like Pont-ker-su(tl)-ter, so 'tougher' is a closer rhyme than 'kilter')