If you have time for only one sight, visit the excellent Whale Museum, a small but cleverly arranged space dedicated to the life of the orca (killer whale), which has become something of a San Juan Island mascot. Among whale skeletons and life-size models of orcas, there are eloquent DVD presentations, interactive maps and details of local research projects, all of which will teach you everything you need to know about these magnificent but cruelly misunderstood sea mammals.