Tenereife and Hawaii as well as been tourist destinations are also
home to major Astronomical observatories.

Should a tourist ever get bored with the Sun, sand, sea and sex what
opportunity is there for such  a tourist to visit / get a guided tour
of the Astronomical facilities on both these islands?

I am particularly interested as to how access to tourists/general public 
compares for both locations (i.e. Tenerife and Hawaii) to their astronomical 
observatories (in terms of guided tours, explanations of research
carried out etc. etc)

Yours Sincerely 

DPRK007

Hi,

   To visit the Northern European Observatory, at Tenerife on the
Canary Islands, you must make an appointment in advance. Here's a
webpage with contact information:

http://www.iac.es/gabinete/difus/ruta/ruta1.htm

   As for the Mauna Kea Observatories of Hawaii, here is a webpage
with visitation details:

http://www.ifa.hawaii.edu/mko/visiting.htm

   It's important to keep in mind that the Mauna Kea site warns of the
hardships of actually visiting the site of the instruments at the
mountain summit, and there are limits to what tourists can expect to
have access to. The road to the top is undeveloped and treacherous,
and the altitude is so high that there is some risk of oxygen
deprivation.