I'm a city person. I can appreciate countryside, but I love exploring urban life. I'm not a typical tourist. I'll skip the museums and the 'typical' dishes. I'll certainly minimise the time I spend with international brands and shopping malls. Instead, I'll search for the stuff that the city does well today. Sometimes it will be food that is grown and cooked well there now, often it will involve a local art or bar scene. Interesting cultures can grow slowly or quickly, but the spirit (for want of a better word) of the residents is always important.

My favourite cities are always large, but fortunately there are a surprising number of large cities in the world. At the weekend I took a look at the largest urban areas by population. Of the 178 listed, I have spent more than a weekend in only 34. I love some of these cities (e.g., Istanbul, San Francisco, Paris, Tel Aviv, Lisbon, Hanoi[1], Cape Town, Beijing, Berlin, Bucharest[1]), but could easily live without others (e.g., Moscow, Casablanca, Frankfurt, Singapore, Hong Kong, Bangkok, Changsha)

I want to find the other interesting cities, and I'm taking the search pretty seriously. There are 144 cities still on the list. So far I've loved about 30% of the large cities I visited, but not really enjoyed another 20% or so. If the statistics are applicable to the remaining cities (I've no reason to believe otherwise), that suggests there are around 45 amazing cities left to discover, but also 30 places I would not enjoy. Random visits are unlikely to work out well.

I'm struggling to see any pattern in my preferences, either by eye, or when I draw scatter plots by GDP, area, population, population density etc (I told you I was serious about this…). Recommendations from others don't help much, either. I've heard great things about many of the cities I did not enjoy, and vice versa. I'm sure there is an element of subjectivity in my choices. Perhaps even the circumstances of my visit made a difference. Yet, the cities I feel strongly about are typically places that I've visited several times, or spent more than a week in.

I've got some ideas, which I'm going to follow up when I have some time. I expect a good prediction formula might involve:

• Recent GDP growth rate (or maybe property value growth rate) (a sensible medium level would be good)
• Length of time as an international trading hub
• Diversity of industries employing residents
• Size relative to other cities that the population can easily reach
• Landscape (a city on the sea, and a city broken up by mountains can help)

If you spot the missing pattern in my list, or have ideas on what makes an interesting city, please let me know. I'll update here when I work out more patterns.

[1] Bucharest is not part of the Wikipedia list because statistics are based on a citizen's official registered home. Re-registering involves up to a full day in a police station. Migration to the Romanian capital is not accurately measured, and likely to be greater than migration in the other direction. A corrected list would have Bucharest at around the same size as Milan or Madrid. I'm sure many other cities also suffer from the same problem. I'm pretty sure Hanoi is one of them.