At Niagara Falls, there's much more to do than going on the walks alongside the Niagara River and by each of the falls. These activities let you experience the grand waterfalls in different and exciting ways. Other tours and excursions let you experience other aspects of the Niagara River and Gorge area. Below is a list of some of these activities and sights though this is by no means an exhaustive list.
Maid of the Mist - this is the oldest running tour of Niagara Falls (dating back to 1846). It's probably still the most popular tour around the falls area. Basically, you're in a large boat along with lots of other paying guests (typically standing room only). The boat launches from either the American or Canadian side and heading right for the three-sided misty torrent beneath Horseshoe Falls. They offer you recyclable rain coats as part of your admission fee because you're going to get wet along with your fellow screaming passengers!
Cave of the Winds - this exclusively American excursion takes you down an elevator into the gorge area where a metal catwalk leads you right up to the base of Bridal Veil Falls. The tour got its name because there used to be an alcove area that allowed you to go behind the falls, which was very windy. That cave was destroyed due to concerns about falling rocks caused by the natural erosion from the force of the falls. The tour provides recyclable rain coats and foam sandals because you're certainly going to get drenched.
Journey Behind the Falls - this exclusively Canadian excursion takes you down an elevator into a tunnel area and lower viewing deck right besides the awesome Horseshoe Falls. The tunnels take you to a pair of openings cut right behind the waterfall. The lower viewing deck is misty and turbulent, but provides quite a rush to be so close to the thundering wall of water.
Observation Deck - this exclusively American structure protrudes out beyond any natural land platform on the Niagara River (besides the Rainbow Bridge for border crossings) for nice views upstream of both the American and Horseshoe Falls. The fee for this deck is included if you do the Maid of the Mist Tour on the American side. There's also a walk that takes you close to the side of the American Falls itself.
Helicopter Ride - this is not exactly the most environmentally friendly way to experience the falls, but you do get a birds eye view of the immense falls. From up here, you'll certainly understand why Horseshoe Falls got its name. You'll also be able to understand the scale and grandeur of the falls.
Jet Boat Tours - these types of tours go downstream from the falls area and into the turbulent Class V or greater rapids of the Lower Niagara Gorge. Thrill-seekers and adrenaline junkies will appreciate the open-air rafts on this excursion. While difficult to pay attention to the surroundings due to the danger of the rapids, it does give you a glimpse of the less-visited Lower Niagara River area.
The Whirlpool Cable Car - the turbulence of the Niagara River and the geology of the Lower Niagara Gorge area combine to form a whirlpool. This excursion lets you ride a cable car above the whirlpool for a thrilling top-down view of it. This tour can be closed due to high winds, however, so it's best to do this excursion earlier in the day when conditions are relatively calmer.