Four hours is enough to experience the highlights of Niagara Falls, but it requires a very disciplined itinerary. In this timeframe, you can realistically accomplish two major things: a walk along the Niagara Parkway to see the American and Horseshoe Falls from the lookout points, and one "hero" attraction like the Niagara City Cruises (Maid of the Mist) or the Journey Behind the Falls. A typical boat tour takes about 20 minutes on the water, but you should factor in 45–60 minutes for the entire process including lines and boarding. After the main attraction, you’ll have just enough time for a quick meal at Clifton Hill or Table Rock Centre before heading back. To make this work, you must book your tickets in advance and arrive during a "shoulder" window (early morning or late afternoon) to avoid the peak midday crowds. While you won't have time for the White Water Walk or a leisurely sit-down dinner, a four-hour "blitz" is sufficient to feel the power of the water and capture the iconic photos that make the trip worthwhile.