Miroslav Sasek's classic children's books are on sale on Gilt... though a quick google search revealed that the sale prices don't seem to beat other online retailers at the moment, if you factor in shipping costs.
We received This is London and This is Paris when our first daughter was born. Having lived in both cities, those books are particularly fun for us to share with the girls.
Since it turns out the Gilt prices are not such a steal, I won't feel bad taking my time amassing a collection, but I was tempted by the 12-pack they are offering. Other versions not included below are Greece, Australia, Hong Kong and Israel.
The wonderfully whimsical illustrations would look great framed.