Abstract Notations can affect the way we think, and how we operate; consider as a simple example the difference between Roman Numerals and Arabic Numerals: Arabic Numerals allow us not only to more easily represent numbers, but also simplify calculations and the manipulation of numbers. One of the innovations of the World Wide Web was the URL. In the last 30 years URLs have become a ubiquitous element of everyday life, so present that we scarcely even grant them a second thought. And yet they are a designed artefact: there is nothing natural about their structure – each part is there as part of a design. This paper looks at the design issues behind the URL, what a URL is meant to represent, how it relates to the resources it identifies, and its relationship with representational state transfer (REST) and the protocols that REST is predicated on. We consider, with hindsight, to what extent the design could have been improved.