There are several company offering hop-on hop-off ...

There are several company offering hop-on hop-off bus tour. The prices are not huge different. This company offers 1,2 or 3 days tour pass. Personally, I think buying 1 day pass is good enough. Because most of the tourist attractions stops are walking distance. Sometimes the wait for the bus and the ride is longer than walking to the next destination. Sometimes the wait for the next bus could be one hour long.....

Besides the audio self-guide, there is also a real guide on the bus. My favorite tour guide has to be WARREN!! He is super entertaining and hilarious~ He has super good memory of where you are from. He would acknowledge you if he sees you again! Super friendly~ He has good jokes and sometimes I didn't even want to get off the bus!!