If there's one word that sums up our most popular projects of 2015, it's "diversity." The list features architects ranging from old favorites such as SANAA, Diller Scofidio + Renfro and OMA down to newer names like Sculp[IT] and Tropical Space; it also includes everything from museums to multi-family housing and spa retreats to chapels - along with the usual smattering of private residences. Interestingly, this year's list also shows the symbiosis between great architecture and great photography, with no less than 4 projects also appearing in our most bookmarked images from this year's World Photo Day. But despite their diversity, there's one thing all of these 20 projects have in common: great architecture. So settle in, relax and read on - here's our 20 most popular projects of 2015.

"Every picture tells a story" - at least, that's according to that great philosopher of our time, Rod Stewart. But what about the stories behind the pictures themselves? At ArchDaily we know that a great image requires not only great architecture but also a skilled photographer, so to celebrate World Photo Day we decided to find out more about the most popular images on ArchDaily. We've taken the ten most bookmarked images in My ArchDaily, and contacted some of the photographers to find out more about their images - read on to see the top ten, and to find out the stories behind six of them.