SUMMARY: Our Siberian Husky had nuthin' on this beagle.
My Siberian Husky, Sheba, who lived to be 17, was one of the canine world's Houdini reincarnations. She went under, through, or over every fence that we concocted. We put her on a tie-out in the yard (a long line on a pulley so she had a lot of room to move), and she'd slip out of her collar no matter how tightly we fastened it, and you should've seen our jaws drop when, after the first time we buckled her firmly into a harness, we arrived home to find an empty, still-buckled harness attached to the line. In the house, she could pop the security bar out of the window, flip the latch, push open the window and the screen, and be gone in under 3 minutes. At about age 12, she learned how to lift the heavy iron L-bar latch on the big wrought-iron gates in our driveway and pull the gate open.
Here's a video of a beagle named Sofia who tops even those stories.