Solo trip to Europe, looking for advice on itinerary

Hello everyone, I’m planning a 4 month solo trip in Europe from September. I’ll be staying 3 months in Schengen, and 1 month in the UK after that. My main focus is history , architecture, streets and just walking around. I’m not that into food, alcohol or nature. This isn’t my first solo trip but it’s my first time in Europe so I’m looking for advice or feedback on my itinerary! :)

**Itinerary**

* Paris
* Day Trips : Versailles, etc.,
* Lyon
* Marseille
* Day Trips : Aix-en-provence, Cassis
* Nice
* Day Trips : Monaco, Cannes & Antibes, Menton & Eze, Villefranche-sur-Mer
* Rome
* Day Trips : Vatican City, Tivoli, Pompeii, Ostia Antica
* Florence
* Day Trips : Cinque Terre, San Gimignano & Siena, Lucca & Pisa, Livorno
* Bologna, Ravenna, Ferrara
* Milan
* Day Trips : Bergamo, Lugano
* Verona
* Venice
* Day Trips : Murano, Burano
* Salzburg
* Vienna
* Day Trips : Bratislava
* Prague
* Berlin
* Hamburg
* Amsterdam
* Day Trips : Edam, Volendam, Zaanse Schans
* Ghent
* Day Trips : Bruges, Brussels
* Cologne
* Munich

What do you think? Would you spend more or less days in some cities? Any feedback, suggestions or advice will be greatly appreciated! :)

Edit : Added day trip locations for clarity!

Solo trip to Europe, looking for advice on itinerary