I too only learned of Chiloé through the UNESCO website. On a recent trip to Chile a friend and me visited as many of the churches as we could while based in the beautiful "city" of Ancud. The churches' designs are surprisingly sophisticated and beautiful. These things were built with love and care. You should go.

Important: as with most UNESCO sites: pay attention to the area surrounding it - they make the best part of the trip! Chilotas* were friendly and their food delicious (try the traditional Curanto!) and their culture rich in myths and legends; some of them downright diabolical. I found it odd, but I realized that any area that has such a huge religious presence begets a reaction. This, however, I only found in the booklets with traditional myths and stories that you'll see in every park.

*Initially "locals" seemed a tad unfriendly and dry (although not rude) until we started meeting native Chilotas who complained that these people are from other regions and give Chilotas a bad name.