The city of Iloilo is consists of seven districts, six of whom were former towns or independent city namely: Arevalo, Jaro (formerly a town before becoming an independent city), Lapaz, Mandurriao, Molo, City Proper while Lapuz which is formerly a part of Lapaz, was declared a separate district in 2008.
Arevalo - was named La Villa de Arevalo by Governor-General Gonzalo Ronquillo y Peñalosa in memory of his hometown in Spain.
District of Jaro - the former name of Jaro is Salog. With the arrival of the Spaniards in the islands, they have no idea about the local dialects of the natives. They walk around in the place to view it and to learn about its name. Incidentally, a Spaniard stopped by Barrio Cubay. He saw a man building a house. He is so busy carving and cleaning the bamboos to be used as flooring for the house. The Spaniard asked the name of the place. The man could not understand what the Spaniard is saying so he just answered "salog" (floor).
In another occasion, a group of Spaniards came to the place. Upon their arrival, the natives were so busy in crafting clay jars that they call "saro." A Spaniard ask the name of the place. The natives assume that he asked about the name of the object they were doing so they answered saro. Since then, the place was called Saro that eventually became Jaro.
Iloilo City Wikipedia Entry
Iloilo City Government Official Website - www.iloilocity.gov.ph