Esgaroth, or Lake-town, is a fictitious community of Men upon the Long Lake which appears in the 1937 novel The Hobbit by J. R. R. Tolkien. Constructed entirely of wood and standing upon wooden pillars sunk into the lake-bed, the town is south of the Lonely Mountain and east of Mirkwood. The town's prosperity is apparently built upon trade between the Men (descendants of the Edain and thus distant cousins of the Dúnedain of Gondor), Elves and Dwarves of northern Middle-earth.
Esgaroth and Lake-town may have been separate settlements established on the same site, one predating Smaug's destruction of Dale and Erebor and the other built afterwards. There is mention in The Hobbit of "old pilings of a greater town" that could be seen at low tide.
Esgaroth appears to be a city-state, always independent of Dale, and a republic with no king (the only real republic shown in Middle-earth). The people had always elected from among the old and wise the Master of Lake-town and did "not [endure] the rule of mere fighting men."
Falling towers were held by arms, but thus as weakness struck its seize,
the jolts of peace were torn apart... (remember men to dwell with roofs)
Building bridges to stand forever, there will be the ones who trail
Floating low or sinking high, there will be the ones who trail.
Redeem the pain that dwells in her, as the end of light beholds you.