In cities, some seemingly harmless places may also become places for drug transactions. These places are often used by criminals because of the large flow of people or the relatively hidden environment. Here are some common examples: 1. **Public transportation stations**: Such as subway stations and bus stations, because of the large flow of people, it is easy to conceal transactions. 2. **Near nightclubs and bars**: These places usually have a large number of customers and are relatively hidden at night, often becoming high-risk places for drug transactions. 3. **Parks and playgrounds**: Especially at night or when there are few people, they may become places for transactions. 4. **Parking lots**: Especially underground parking lots in large shopping malls or entertainment venues, due to their relative concealment and blind spots of surveillance, they may be used. 5. **Areas around campus**: Near schools in some urban places, sometimes become high-risk areas for adolescents to come into contact with drugs. 6. **Fast food restaurants and convenience stores**: These places have frequent flow of people and short stay time, which makes it easy to conduct quick transactions. 7. **Short-term rental apartments or hotel rooms**: Because transactions can be conducted in the room, it is relatively difficult to be noticed. Urban environments are complex and these areas, by their very nature or environmental characteristics, may be easily exploited by illegal activities. Strengthening surveillance and public awareness in these areas is very important.