With its volcanic mountain peaks and lush, forested interior, St Lucia looks like an island uprooted from the South Pacific and plopped down in the Caribbean. Like the Caribbean island of Saba, St Lucia is more renowned for its rugged, volcanic interior than for its ring of sandy beaches. The island’s dramatic twin peaks, the Pitons, tower more than 700 meters above the sea, sheltering dense, flower-speckled rainforest, bubbling mud baths tan-colored beaches and quaint, laid back fishing villages.   THINGS TO DO IN ST LUCIA ON A BUDGET Exploring St…