The central market is in the city's historic centre, in Zone 1 and behind the cathedral. It is hidden beneath a parking lot and square, but don't be mistaken: it is a vast maze of 2 or 3 floors! Don't hesitate in going in, once inside you will discover an entire world. Food stalls and restaurants where you can buy cheap traditional food (less than 2 € for a menu). Try exotic fruits and vegetables or something local if you prefer. Candles, baskets, plastic, a bit of everything! The part that is sure to interest you the most? Half the level is dedicated solely to souvenirs / memorabilia. In my experience that's where you can get the best prices (much cheaper than the markets in area 13, and slightly cheaper than the market of Antigua if you can haggle). Feel free to wander around and barter. There do not tend to be many tourists in the area, and there's one thing you must not forget: watch your bags! pickpockets are also active in Guatemala!