Sator Square

Found in the ruins of Pompeii, the Latin inscription SATOR AREPO TENET OPERA ROTAS (“The sower Arepo holds the wheels with effort”) may be the most symmetrical sentence ever composed. If it’s written conventionally, it’s a palindrome, reading the same forward and backward. And if it’s written into a square:
Image: Wikimedia Commons

… it reads the same left to right, top to bottom, right to left, or bottom to top.