Roy Badami wrote on 28 September 2010 23:13:13 ...

The Smile passageway is so called because...
http://www.flickr.com/photos/67655316@N00/225943955/

Because ....?

Because, I assume (although it is not incredibly easy to read in that
photograph), the design on the inside of the tunnel is actually letering
that says "SMILE"

Oh, I see! I thought the splodges of colour were national flags or
something; didn't realise they were letters.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)