This little museum is hidden away up an alley off Calle Linares aka ‘Gringo Street’ due to all the travel agencies and clothing or crafts shops. 
Whilst tiny in size it is bursting with information about the little green leaf that has been held sacred in the Andes for centuries. The displays themselve look a little worn and the whole setup can seem a little amateur, but if your patient enough to follow the self guided tour whilst reading the provided infomation in your own language (available in many languages) you will no doubt learn plenty of facts you didnt know about the coca plant.
Covering the use of the coca leaf in traditional andean socities for spiritual, medicinal,social and other purposes, right up to exploring the modern day ‘drugwar’ against cocaine. The information is provided in a scientific way backed with lots of evidence to back up its theories but still manages to remain unbiased. Including sections on the use of the coca leaf in Coca-cola, for coca wine, as an anesthetic amongst others it certainly provides some evidence to justify the ‘la hoja de coca es no droga’ (the coca leaf is not a drug) campaign seen on tshirts and posters throughout the peru and Bolivia.
If reading through lots of information is not what you consider a good way to spend 30 - 45 mins then you may find this museum a little dry (my brain slowed a little before id finished) but if you have a interest in andean culture and would like to learn the truth about coca then this popular tourist attraction is a mine of information and worth the cover fee of around US$1.

Museo de la Coca
Calle Linares 906
La Paz
Tel 231-1998