Related Clues:
- Greenhouse gas victim
- Lunar depression
- Manmade waterway
- Ottawa Region's Rideau______
- Structure with locks
- Place for a low bridge
- It may have locks on it
- Man-made waterway
- Top-of-the-world topper
- Serious depression
- Percival Lowell "discovery"
- Gondola setting
- Moon cavity
- Mountain peak covering, often
- Suez waterway