Sloan's is an amazing sensory experience, with its hot-pink walls, giant lollipops, miniature choo-choo train, 47 flavors of ice cream, and toys, toys, toys! But the most amazing part is the bathrooms -- which have clear glass doors that look right in to the throne. When you venture in and turn the door handle, however, the glass fogs up and becomes completely opaque. An investigation by the Travel Channel -- which named this the tenth best bathroom in the entire world -- revealed that the door is actually made of two panels of glass. Sandwiched between the panels is a mixture of polymer and liquid crystals. A constant electrical current keeps the crystals in line and the glass transparent. But when the door handle is locked, the current is stopped, the crystals fall, and the glass looks clouded. For a cheap thrill, you can spend all day playing with the bathroom door. Better yet, take a friend, feed them a couple of bottles of water, and get a kick out of showing them the way to the loo.