The Anchor Symbol

2nd or 3rd century
Crypt of the Church of Santa Cecilia in Trastevere, Rome

The anchor is an early symbol for Christ. The iota and theta to the left and right of the anchor are the first letters of the Greek words for "Jesus" and "God."

See also Crosses and Crucifixes

Photographed at the church by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.