In Canggu, there is a so-called farmers' market every Sunday.
A lot of people gather there. You can safely come with children: they can walk around and draw.
There is also a nice café with vegetarian food. If you arrive by 12 PM, you might miss all the fun that happens there in the morning and many of the vendors may already be gone.
They sell everything from jewelry to various foods/vegetables/fruits.
Prices are quite high.
