Whether you need a passport for Niagara Falls depends entirely on which side of the border you intend to visit and your country of citizenship. If you are a U.S. citizen visiting only the American side (Niagara Falls, NY), you do not need a passport as it is domestic travel. However, to cross the Rainbow Bridge or the Lewiston-Queenston Bridge to the Canadian side (Niagara Falls, Ontario), a passport is the standard requirement. For U.S. citizens traveling by land, alternative documents such as a Passport Card or an Enhanced Driver’s License (EDL)—currently issued by states like New York, Michigan, and Vermont—are also acceptable. U.S. children under age 16 traveling by land only need a birth certificate to enter Canada. If you are flying into Canada (e.g., to Toronto Pearson Airport) to visit the Falls, a full Passport Book is mandatory for all ages. It is highly recommended to bring a passport regardless of your plans, as the best panoramic views and the famous "Journey Behind the Falls" attraction are located on the Canadian side, and crossing the border is a highlight of the trip.