The principal shopping area in Istanbul is, undoubtedly, the Grand Bazaar, with more than 4,000 shops crammed beneath its roof.
There are less than a dozen shops in the Grand Bazaar in Istanbul. 
mnli hypothesis: There are less than a dozen shops in the Grand Bazaar in Istanbul.  premise: The principal shopping area in Istanbul is, undoubtedly, the Grand Bazaar, with more than 4,000 shops crammed beneath its roof.