There are 68 cities in the UK, and I once hosted a dinner party where a quiz round was to identify each city given its location on the map.
This made me realise how few of these places I had actually visited, and a quest was born: to visit each city. This seemed an ideal retirement occupation
As with any task of this nature, some rules are required. First of all I felt I should stay at least one night in the city, a fleeting visit to the railway station would not count. And that's it for rules