Krung Thep Mahanakhon Amon Rattanakosin Mahinthara Ayuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udomratchaniwet Mahasathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit, meaning the 'City of Angels', is known to the locals as Krungthep Mahanakhon. The rest of the world knows it as Bangkok, Thailand. However, it is not recognised by the Guinness Book of Records as the longest place name as it is not used on a daily basis by the locals.
The place with the longest name in common usage is a 252 metre high hill in Central Hawke's Bay, New Zealand. Taumata whakatangihanga koauau o tamatea turi pukaka piki maunga horo nuku pokai whenua ki tana tahu translates as the 'place where Tamatea, the man with the big knees, who slid, climbed and swallowed mountains, known as land-eater, played his flute to his loved one'. This is the place name recognised by the Guinness Book of Records. It is sometimes written without the spaces as one long word.
Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch currently has the prestige of having the UK's longest place name.