Niagara Falls, both the U.S. side and the Canadian side. Robert and I have been there many times -- including in the winter when everything is covered with ice and snow -- and yet we always find new things to see and do. It's an amazing (and VERY romantic) place to visit!
Grand Hotel, Mackinac Island, Michigan. "The icon of Mackinac Island is the Grand Hotel. Built in 1887, the hotel is elegant and charming and has the longest summer porch in the world." via flickr.com/photos/mackinacisland/