At level 34 the Caravanner's Wigwam will become available. After rebuilding the building you will be able to send caravans to distant cities and get rare goods.
Click on the Caravanner’s Wigwam to open the caravan sending window. Here you can send available caravans, speed up those on the way, or collect goods from already arrived caravans.

Each town is rich with its own unique goods:
  • Garden Springs: Olive, Pear and Lemon. Available from level 34.
  • Wild Peak: Leather, Fur and Silk. Available from level 40.
  • San Hernandez: Avocado, Peanuts and Bananas. Available from level 46.
  • Chinatown: Rice, Coconut and Tea. Available from level 57.
How do I increase the number of caravans?
At the very beginning you will have one caravan available. But with time, their number can be increased to four for each city. You can buy more caravans from a caravanner, once you reach the required level and population.

How do I get a chest and rare goods in caravans?
Simply add one of the horseshoes to the caravan before shipping. More valuable horseshoes increase the likelihood of getting more goods. Additionally, you will have the opportunity to get a chest with a valuable reward. The more valuable the horseshoe, the more likely you are to get the chest.
A caravan sent without a horseshoe will return without a chest. You can temporarily increase the effectiveness of horseshoes when sending a caravan by using the "Valuable Horseshoes" prediction at the Fortune Teller.