Tightrope walker Nik Wallenda signed photo. 11x8 inches Nikolas Wallenda is an American acrobat, aerialist, daredevil, high wire artist, and author. He is known for his high-wire performances without a safety net. He holds 11 Guinness World Records for various acrobatic feats, but was best-known as the first person to walk a tightrope stretched directly over Niagara Falls.