Related Clues:
- Design feature of many a viaduct
- Bend over backward
- ___ of Constantine (landmark in 45-Across)
- It's big in St. Louis
- Rock formation
- St. Louis symbol
- Way over the Charles
- Roman construction element
- Four-handed card game
- Lift, as one's brow
- Eyebrow or rainbow
- Semicircular entrance
- Bend backward
- ___ enemy (one who may blow up bridges)
- Classy entranceway