Great Lakes Lighthouses Wall Calendar shows a selection of pictures of lighthouses from all five of the Great Lakes. With well over 200 lighthouses, the Great Lakes have the largest concentration of lighthouses to be found anywhere in the world. The styles of structures seem endless, ranging from a single tower to multiple dwelling accommodations for the keepers. Most of the important lights are still in service. Many are cared for by dedicated volunteers and have museums open to the public. Two additional interesting pictures are shown each month and there is ample space for writing in dates and appointments. Wire-O binding allows the calendar to hang perfectly flat. Pictures on each page are printed on heavy high-gloss card stock.