
A boulder in Reinhardt Canyon carved with a deep square maze, real enough to touch and nobody knows who cut it. The safest read is native Rancho Bernardo-style rock art, a geometric tradition found across Riverside and San Diego counties; the wilder theory says shipwrecked or exploring Buddhist travelers left it centuries before Columbus, since the pattern echoes an old-world symbol. California made it Historical Landmark 557 and fenced it; the mystery is the one thing that never eroded.
Reinhardt Canyon near Hemet (Riverside County)
See it on the map