No secret passage behind waterfall

A group of intrepid children yesterday stunned archaeologists by claiming that
they had discovered a waterfall which did not conceal a secret passage.

The discovery was made by Julian Kirrin, accompanied by his brother Dick.
Their sister Anne and cousin George were temporarily unavailable for comment,
having been captured by gypsies. 
"We were investigating a group of swarthy rogues acting mysteriously on the
moors at night," explained Julian, "and we noticed this waterfall close to
where we had seen strange lights last night.  So I carefully edged behind the
curtain of water, looking for the secret passageway leading to the cove, and it
just wasn't there.  I just didn't understand it. 

Noted archaeologist and genetic freak, Dr Lara Croft was sceptical.  "I don't
believe this myself.  There's always a secret passage behind the waterfall.  I
don't think these kids were trying hard enough.  Did they jump up twice their
own height and try to grab on with their fingers?  Did they push hard against
the flat stone wall while making a strange sexual grunting noise?  Perhaps they
should have jumped off the top of the waterfall and swum around in the pool
looking for a health pack or a secret lever."  she said, whilst performing back
flips around her English country mansion.  Dr Croft (BA Cantab MA Oxon BRA
Brunel) then added, "Does my bum look big in these shorts?"