A couple weeks back, we ran a quick hit on the Soumaya Museum in Mexico City, billionaire Carlos Slim's gift to the D.F. skyline. Museum buildings are now as much a part of the show as the art housed inside, so banking off of Mexico's new architectural feat, we went through the files to share the greatest museum architecture in the world with you. Click on the gallery above to see the 10 coolest museum buildings in the world.