according to those good people over at Wiki:
"Saint Ia of Cornwall (also known as Hia, Hya, Eia or Ives) was a 5th or 6th century Cornish evangelist and martyr. Ia was said to have been an Irish princess, a spiritual student of Saint Baricus; she travelled as a missionary to Cornwall - on, as legend has it, an ivy leaf - where she joined Saints Fingar and Piala and their 777 companions*. Ia was martyred on the River Hayle and buried at St Ives, Cornwall, where St. Ia's Church, St. Ives, of which she is now the patron, was erected over her grave. The town built up around it. "can you see the church in the photo? the greenery behind it is where you'll find the Hepworth Museum. . .
*do you think this is where the number seven in the nursery rhyme comes from?