You can walk across Valletta in twenty minutes, which is exactly why it rewards slowing down.
Walk in through City Gate and let the grid of honey-coloured limestone streets do the work — every corner reveals another Baroque church facade or a balcony painted the deep green the city is known for. St John's Co-Cathedral looks plain from outside and almost unbelievable within; save an hour for the Caravaggio alone.
Climb to the Upper Barrakka Gardens for the wide view over the Grand Harbour, timed if you can for noon or six, when the saluting battery below fires its cannon in a small daily ceremony that draws a crowd without ever feeling like a show. The harbour itself, still busy with working boats, is what makes Valletta feel lived-in rather than preserved.
Take the short ferry across to the Three Cities for a quieter, less-visited version of the same architecture, then come back for dinner in one of the tiny family-run restaurants tucked into the old town's side streets. Valletta closes early and opens late by Mediterranean standards, so plan meals around a leisurely two-hour lunch rather than a late dinner — the city keeps gentler hours than its neighbours.