Why? It's thought to be the most beautiful city in Iran, which means it is probably the most beautiful city in the Middle East. It's certainly one of the most exquisite cities in the world. I lived there for four very happy years until 1976. I found the place and the people to be quite wonderful.

The best thing: The visual beauty of the city. The Masjid-I-shah, or Imperial Mosque, has a dome of vivid blue tiles and there is a 40-arch arcaded bridge which is one of the most remarkable I have ever seen. It also has ruined gardens, and one of the biggest bazaars in the Middle East. And the ancient city is steeped in history.

My ideal day: I'd head off to the bazaar to look up two old friends who I know are still there. One sells carpets and the other antiques. I'd spend my time with them and as we talked, we would drink endless cups of tea. We'd also eat well, which they do in Iran.

My advice: You should be respectful of a culture that is so much older than ours and equally sophisticated. Also, it is a city high above sea level, so be prepared for an altitude change.

Getting there: Cheapflights (cheapflights.com) has flights between Tehran and London Heathrow and London Gatwick from around £339 return.

Crime writer Donna Leon's latest novel, featuring police detective Commissario Brunetti, is Wilful Behaviour (William Heinemannn, £15.99). It was published on Thursday.