Niagara Falls has all kinds of reasons to get outside in the summer. It is a haven for anyone longing for laid-back leisure. And anyone looking for outdoor excitement will be equally happy. Start with the thunderous falls. What could be a greater rush than standing near 3,160 tons of water thundering by each second? You can enjoy a picnic beneath blue skies or swoop over the Niagara River at a dizzying height. Here is a sampling of attractions.