The mercado
The "mercado" is located about 3 blocks directly west of the northwest corner of the town center. the market is opened every day, but is largest on saturday, monday, and thursday. it is big, like a maze, and you will likely lose your way and never encounter your friends again. it is dark in the covered areas, and brighter on the outside sections. the cheapest food, commodities, fresh meat, and gifts are found here.
Inexpensive tropical fruits
Also found in the "mercado". vine ripen fruits, papayas, plums, mangoes, cherries, strawberries, melons and other delicious unusual tropical fruits are available in abundance with seasons varying. the red curly haired "lychas" have a pleasant sweet taste like the lychees found in cans in the u.s. fruits are safe food to eat if washed. one might stay away from strawberries, unless you can assure of a good soak in bleach to wash away any "fertilizer" or contaminated irrigation water.
When you change money at the bank, you will need your passport. Banks are open 7 days a week, and open until 7PM-8PM. Most of the time, a passport is not needed for changing dollars into quetzales. However, you are likely required to have a passport if you want to redeem traveler's checks. ATMs are also available, but read the charges well before completing the transaction. The ATMs and banks near Parque Central offer the most reasonable exchange rates.