In general, there are no unsafe spots in the city best avoided. The streets are safe, even at night, although you better avoid public gardens at night. Even though most of them have closing hours which vary throughout the seasons. Of course, it is advised to take the precautions tourists are urged to take everywhere (e.g. to avoid pickpocketing). If you have a bike, make sure it is secured with a decent lock as students tend to 'borrow' bicycles. Similarly, jackets left unattended in bars may be at risk.
