The first half of the film, after the opening and closing sequences shot in possibly Surrey, is entirely set in London and demonstrates a cleverly mapped series of movements in the city which I have pinpointed here:
What Mann does is keeping every transportation within the logic of city space, hence drawing a map on audience's mind which increases the relation between the drama and the place.
Even the Berlin part, a city which I barely know, benefits from the same intensity and accuracy of cinetopographical mapping. I believe it is the same consistency which gives an authentic feeling to Mann's even older, studio-built films such as Side Street (1950).
The exterior movement of A Dandy in Aspic, as you see marked on the map in order of their introduction in the film, develops like this:
1: Café Royal, 68 Regent Street.
2: Albert Terrace Mews. Outside Mia Farrow's studio.
3: Driving from Mia Farrow's to the south, via Battersea Bridge
4: A spy in wait to meet his contact. It must be a location close to Saint Thomas' site.
5: Laurence Harvey meeting a Russian agent in what seems to be under Bridge City pier or London Bridge.
6: Outside a council house on Cable Street, E1, where the Russian agent gets killed.