Easy
If you're going in Summer, always remember waiting for a bus will be hot work, and walking distances between Monorail stations and the hotels they join to are often much longer than you expect. HOWEVER, public stransport is all air conditioned, and a bargain.
Bus
Las Vegas for tourists is basically one long road (Las Vegas Boulevard), and a bus runs down that road from The Strip all the way Downtown. One ticket will last you all day, but you must have the right change, so its best to buy online or in advance.
Monorail
The Monorail is easy and fun, but remember the stops are at the back of the hotels, which in vegas means a loooong walk, up to 20 minutes, from the front of the hotel. It won't take you all the way downtown, but runs the length of the strip.
How
You can ride the full length all day for just a few dollars (one tickets) and its super easy.
for monorail and bus buy on the day with cash, or click 'more' and then 'transportation' at vegas.com.
