How about the hill in New Zealand called Taumatawhakatangihangakoauawotamateapokaiwhenuakitanatahu
Or try these official words:
hippopotomonstrosesquipedalian
lamprophony
finnimbrun
floccinaucinihilipitification
phenakism
pulveratricious
rastaquouere
scopperloit
tyrotoxism
zaberism
gambrinous
gargalesthesia
spiffing
or this word for the day before yesterday: nudiustertian