the greenery, architecture, but for a city lover like me not worth it

Tibet is awesome! It has been one of my favorite places to visit in China by far. The mountains and lakes and rivers in and around the city are breathtaking. Most of the "things to do" in Lhasa involve visiting temples and monastaries. The Potala Palace is a must. It's not a "typical" city like in Mainland China. It's much smaller and there aren't a lot of cars or anything. Lhasa is very traditional still, with prayer flags everywhere and people still wearing traditional clothes. If you want to get a glimpse of traditional Tibetan culture and see amazing scenery, it's a great place to visit.