Greece
Get actively involved in sea turtle conservation. Archelon, The Sea Turtle Protection Society of Greece, provides a chance to track nesting turtles and their hatchlings, hone your public speaking skills and live on communal campsites with international volunteers (May - Sept). Alternately help out at the rehabilitation centre in Athens (all year round). It doesn't cost thousands of pounds either - just 150 euros.
For application details see www.archelon.gr
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