It takes roughly an hour to drive from Khiva to Biruniy and a further hour to get to Ayaz

Location
It takes roughly an hour to drive from Khiva to Biruniy and a further hour to get to Ayaz qala via Bostan. 

However if you are making a round trip it is better to visit Topraq qala first. It's then just 20km from Topraq qala to Ayaz qala as the crow flies, although it takes about 32km by road. Leave on the main road running in front of Topraq qala in a south-east direction. After 10.5km, just as the main road bends to the right, take a left side road which crosses a small canal. After a while the road heads in a straight north-easterly direction running parallel to a narrow canal on its left side. 15km from the turn the road bends towards the north. After a further 4.2km you cross another canal and continue for a further 1km. As the road bends to the right, you continue straight ahead on a rough mud track with good views of the sites of Ayaz qala 1 and 2 ahead. After another 1.2km up the escarpment you arrive at the Ayaz qala yurt camp.