In Khiva, beautiful lighting has been installed throughout the old city (Itchan-Kala). The lighting is turned on at sunset. In Samarkand, the Registan is beautifully illuminated. In Bukhara, the lighting is more modest, but at the Ark Fortress, you can negotiate with the local guards to go up to the wall, which offers a view of the illuminated evening Bukhara. They approach and offer, and from there, it depends on your bargaining skills.