"So give me a kiss by the Long Canal, and give me two kisses in Salty Town, for we're going to die tomorrow! The bareheaded beggar, the king with his crown..."
―Mace Tyrell serenades Tycho Nestoris[src]

Salty Town is presumably a suburban area of Braavos.

Mace Tyrell performs a boisterous Braavosi ballad in which Salty Town is mentioned to an irate Tycho Nestoris.[1]

In the books

In the A Song of Ice and Fire novels, the Salty Town is never mentioned, although Braavos does have several suburban areas, including the Drowned Town.

Mace Tyrell never travels to Braavos in the timeline of the books, and so his tuneless rendition of the Braavosi shanty is never heard.