Four days among four cities that are not much alike
From the coast and from Garda everything is a day trip.
The Veneto of the cities works very well as single days, because the distances are short and the trains run. These four days leave the campsite in the morning and return in the evening: one by boat, three by train or car.
Venice
From Punta Sabbioni, at the tip of the Cavallino peninsula, the vaporetto reaches San Marco in a little over half an hour and the car stays in the car park: it is the best way to go. From Padua and Treviso you go by train. One day is enough for San Marco, the Grand Canal, Rialto and a couple of quarters on foot; the museums and the islands want a second day.

Verona
Verona can be walked in half a day: the Arena in Piazza Bra, via Mazzini, Piazza delle Erbe and Piazza dei Signori, the Ponte Pietra and the climb to Castel San Pietro, from which the whole city is visible inside the bend of the Adige. In summer the Arena holds the opera festival, and a performance at nine in the evening is the reason to stay.
Padua and the hills
Padua has the Scrovegni chapel, frescoed by Giotto between 1303 and 1305 and visitable only by booking with timed entry, the basilica of Saint Anthony, the Prato della Valle, which is the largest square in Italy, and the botanical garden of 1545, the oldest in the world still in its original place. In the afternoon you climb into the Euganean hills, between Arqua Petrarca and Monselice.
Vicenza and the villas
Vicenza is the city of Andrea Palladio: the Basilica Palladiana in Piazza dei Signori, the villas and palaces along the corso, and the Teatro Olimpico of 1585, the oldest surviving indoor theatre, with a fixed stage set in perspective. Outside the city stands the Rotonda, and in the countryside around it the other villas scattered between Vicenza, Treviso and the Brenta.