We had a 1 day tour to terra-cotta warriors and city wall in Xian at the begining of May 2010.
David was our tour guide.He was very nice, spoke very good english with perfect knowledge about history, culture and habits so we lernt a lot during our trip.
Terra-cotta is amazing place which everybody shouls see during holiday to China.
We spent some minutes in City wall in Xian but it wasn't good because most of time we saw museum and shop.
By the way i recommed this tour to everybody!