The Colosseum. It's headed toward the Colosseum.
4 seconds sound clip from the 20 Million Miles to Earth (1957) movie soundboard.
You can hear this line at 01:14:28.915 in the Blu-ray version of the movie.
Quote context
[...]
- Anything there, Bob? No, general. We don't spot it here.
- We've blasted the Tiber straight through the city for hours now. Got any ideas?
- Hello? Bob. Can you hear me?
- Do you hear me, Bob? Come in, Bob.
- It's here, general. At ponte Sant'Angelo.
- The Colosseum. It's headed toward the Colosseum.
- Sergeant, take your men up those stairs.
[...]