Abandoned footwear, such as a lone boot or shoe, has often been noted in out-of-the-way places like ponds or by the side of roads. Sometimes the shoes may even be new and fashionable. There are many hypotheses about why this phenomenon seems to more often involve footwear than other types of clothing. Shoes, being more sturdily constructed than most other types of clothing, will last longer after being abandoned outdoors. Leather shoes, for instance, are estimated to last for 25–40 years outside. Some shoe abandonment is intentional, as in shoe tossing, in which shoes are tied together by their laces and thrown in great numbers into trees, over power lines, or over fences.