The largest concentration of contemporary-art galleries and design studios (mainly expatriates’ work) is housed in the trendy Fábrica La Aurora, a remodeled raw-cotton factory on the north end of town.
It's a huge complex that's worth a visit even if you're not planning on buying. As well as the chance to browse the shops here (if you're intending to buy be aware that this is all high-end, expensive art) there are also regular exhibitions, events and art-related workshops. The site also contains a nice cafe.