Hi kathy,
Are you using your mini-map at the top of your screen? I found it incredibly helpful when playing this game. Follow the direction of the blue arrow and it'll lead you straight to the snake temple. Remember that a blue arrow means the location is at a higher level to that which you are currently at, so you'll need to climb steps.
For guidance:
The green arrow shows that the mission location is at the same level as Oliver. The blue arrow shows a higher level and the violet arrow shows a lower level than where Oliver is at that moment.