Here is the comment of f.formica: Originally, Italian had two triplets of place adverbs, qui/costì/lì and qua/costà/là, respectively close to me, close to you and far from the both of us; the difference between both groups was the the -a ending one indicated a wider area than the -i ending group, which indicated a specific location. Nowadays costì and costà only survive in Tuscany and some literary circles, and lì/là are basically synonymous, as are qui and qua.