Night food bazaar (opens around 8:00pm) serving local specialties like bhutte ka kees, garadu and chaat — lively and great for sampling many small dishes.
A one-hour boat cruise gives classic views of the City Palace, Jag Mandir and lakeside ghats — book late-afternoon boats (typically run until ~6:00pm).
Large hilltop fort with ornate halls and courtyards; open from about 8:00am–5:30pm — allow 2 hours and consider the elephant-free approach (jeep/walk) for sustainability.
Chokhi Dhani opens ~7:00pm and offers an ethnic village experience with dinner and performances (book if you want a festive final evening); otherwise use this time to prepare for departure from Jaipur by road/train/flight.