Lets see, walking from the Main Entrance Plaza to the west end of Downtown Disney (ESPN Zone and the security check station) is close to 1/4 of a mile. Now, how long? Well that depends on how fast you walk,and how prone are you to be distracted and stop to "smell the roses". The entire area is inside the security zone, so that is not an issue. But you are going to walk by shops, restaurants and entertainment offerings, and if you keep stopping to browse, well, that is hard to calculate. Let's say about 10 minutes each way without the distractions, and work from there. But yes, they are right next to each other...