When talking about manholes, mention precautions due to their potential danger if left uncovered. Watch out for the open manhole; you could fall in!
Pro Tip 2/3
City Infrastructure
Manholes are part of city planning, often discussed when issues of urban maintenance arise. The city is mapping all the manholes to plan a maintenance schedule.
Pro Tip 3/3
Utility Workers
Manholes are usually accessed by utility workers, indicating their association with certain professions. The utility worker opened the manhole to fix the underground pipes.