For your visit, excluding any museums, one day is enough to get acquainted with the city.
Distances are walkable in most cases.
Worthy attractions: Musée de la Villa Masséna; Palais Lascaris; a number of churches; Colline du Château.
Left for another visit: Musée Matisse; Musée Chagall; Musée des Beaux Arts; Museum of Modern and Contemporary Arts (MAMAC).
Last visit: September 2022.

Nice offers many visually pleasing perspectives and reasonably impressive sights, without looking exceptional on balance. That colored my approach to the exploration of this Mediterranean playground. Using Nice as the Riviera base in 2002, we acquainted ourselves with the city somewhat superficially, and the only dedicated return visit in 2022 was no more than intraday. In other words, like many other visitors to Nice, we kept ourselves to just two key areas: the seaside promenade and the Old Town.
Promenade des Anglais ♥ is a prime people-watching gallery. On a pleasant day, commandeering a couple of chairs by the guardrail and spending some time idly looking out on the beach and to the sea is a very nice pursuit. And, of course, the city beaches are all here.
Musée de la Villa Masséna ♥ sits right on the promenade (next to the famed Hotel Negresco that you apparently cannot just visit without staying there). The villa is one floor of palatial rooms and two floors of history of Nice looked at from different angles, very well presented and quite interesting. There is a 5-minute movie looping in the ground floor’s Grand Hall alternatively in French and English, but aside from that most of the information is in French only.
The reasonably compact Old Town ♥ is quite Mediterranean in look and feel, and definitely worth exploring. Here you can find a number of impressively ornamented churches, most notably, Église de l’Annonciation ♥♥ (aka “Sainte-Rita”) and Église Saint-Jacques-le-Majeur ♥♥ (aka “Church of Jesus”). The timing and temporary closures worked against us for also visiting Cathédrale Sainte-Réparate and Chapelle de la Miséricorde.
One museum in the Old Town that we visited was Palais Lascaris ♥, which combines fine Baroque features with a fun collection of vintage musical instruments (and a few smaller collections).
The market in Cours Saleya ♥♥, marking the southern boundary of the Old Town, is a daily delight of flowers, vegetables, local products, etc. To the east, the Old Town abuts Château hill ♥, an elevated park with unrivaled views over the city and an artificial waterfall. There are other green spaces around the Old Town, such as Jardin Albert 1er and the newish Promenade du Paillon.
There are nearly a dozen other potentially worthy museums in Nice. Most of them can be accessed on a single and fairly affordable combination ticket. Many of them are located slightly further away from the aforementioned key areas of the promenade and the Old Town, and we did not budget any time for them on our visits so far.
One architectural attraction that we specifically targeted on our first visit in 2002 was Cathédrale Orthodoxe Russe St-Nicolas, the largest Russian Orthodox church outside of Russia. As luck would have it, we arrived during a ceremony, and therefore barely caught a glimpse of the interior.
Places to Eat
In 2022, we had a couple of meals in Nice as a family of three. Both were fairly random selections. A lunch at Le Romarin ♥♥ in the nook of Place Rosetti next to the cathedral walls got high marks, with an excellent menu, nice service, and great choices all around – salade Norvegienne, poulpe à la plancha, and panna cotta for dessert were all top notch; not bad for avid people-watchers too. A dinner at La Storia ♥ on Cours Saleya was somewhat mixed; it is one of the busier places in the busiest part of town. Great food but uneven service (always friendly, at times impressive, and at other times inattentive).
In 2002, we had several dinner meals in Nice, but that was before we started diligently recording the specifics of meals in our diary. Based on what I can surmise, the establishments were Jardins Capitole and West End Hotel on Promenades des Anglais, and Le Milo’s ♥ on pedestrian Rue Masséna. The latter actually prompted a couple of diary notes, referring to the most efficient waiter that we’ve seen on our entire two-week French trip as well as the most delicious Chocolate Pyramid dessert. I also happen to recall that the length of the meal at West End exceeded four hours. But I do not have many recollections beyond that to provide any true recommendations.