The Legos Store at Downtown Disney in Orlando, Florida has more Legos than probably any other place, except maybe for the Lego factory. In the back is a curved wall that has hundreds of round holes containing individual Lego blocks of all shades of colors. You can mix and match any combination you want, or just pick up a hand to replace a few missing from your collections. 

This is a panoramic image from my iPhone. It took a few practice takes to keep things level, without anyone walking through the image. It’s a fun tool and gives a cool view. The curved wall was actually curved slightly inward, though the image looks as if it’s outward. The full size image is actually 10800 x 2385 px, since it stitches several images together.