Khao Rang Hill in Phuket Town is located not far from Tesco Lotus, and if you are coming on the road from Patong Beach, it's easy to find it, just follow the road that goes past the Bangkok Phuket Hospital, continue on that road, you will eventually come to a 4way crossing, where you should turn right, and then look for a road that goes up the hill on the right side, not very far from the crossing. There should be a sign there so you won't miss it. The drive up the hill is quite nice, and there is a few good viewpoints on the way up. The viewpoint offer a view of Phuket Town, and the southern parts of the island, all the way to the Big Buddha. On the way up you will also pass Wat Khao Rang, that features one of Phuket's first sitting Buddha images.
On the way up, near the top is an exercise park located, you can even get a good workout, just walking up the road to the Hill. The Park on the Hill and Viewpoint is a good location for picnickers having a day out in the cool shade of the trees and the nice breeze of the wind at the top.
There is a good restaurant here as well, Tung Ka Cafe, the prices are normal for Phuket Town, and the View and Food is excellent, do give it a try for lunch, or early dinner, getting a good seating here is not to difficult. Even at the evenings this is a popular and romantic place for lovers to enjoy the view of the lights from Phuket Town, and the stars from above.
It's open daily, and a good time to visit is when the weather is great, maybe bring your picnic basket along, or enjoy a meal at the Tung Ka Cafe. Khao Rang Hill in Phuket is well worth a visit, to enjoy a calm afternoon.