Yarkand's old city has survived without the extensive rebuilding that turned Kashgar's old town into a partly reconstructed heritage zone in the 2010s. The result is a neighbourhood that is more dilapidated, less picturesque, and considerably more genuine: mud-brick houses with carved wooden balconies that are actually in use, lanes that are genuinely narrow and not pedestrianised for tourists, workshops that are doing real work rather than demonstrating traditional crafts.
Walking the lanes around the Amanisahan mausoleum and the Altyn Mosque gives the best sense of what an old oasis city looks like when it has simply been left to age rather than being preserved or rebuilt. The buildings mix traditional Uyghur domestic architecture with the practical additions and modifications of generations of use: a new door in an old arch, a plastic water pipe running along a thousand-year-old wall.
The old city is entirely walkable in half a day if you are willing to get slightly lost; the mausoleum complex and bazaar provide orientation points. The people who live here are accustomed to occasional visitors but not saturated with them, which changes the dynamic of walking through considerably.