Gallipoli has two hotel settings: the walled old town on an island and the newer streets by Corso Roma. Baia Verde and the northern beaches put you by the sea instead, but farther from an evening in the historic center.
Cross the stone bridge beside the castle to enter the old town. The Cathedral of Sant'Agata, the fish market and the lanes around Spiaggia della Purità are all on the island. Sunset walks start at your door. Ask about luggage access, because most of the historic core is only passable on foot.
Corso Roma runs through the newer town from the station toward the bridge. Pick this side for a rail arrival, shops or easier parking. The old-town sights are still walkable. Lungomare Galileo Galilei runs south along the seafront toward Lido San Giovanni.
Baia Verde has sandy beaches and Gallipoli's summer clubs. Book it for beach days and late nights, then plan a ride back from the old town. Rivabella and Lido Conchiglie lie north of the center. They turn the trip into a beach stay with the odd outing into town.
The Ionian coast is hot and dry in July and August, with average highs around 88 °F. May, June and September are easier for the old-town lanes and the shore. Parking near the island is hard in summer, so ask your hotel how it works before you drive in.