Nkotsi village (also known as Muko) is a small village 7km southwest of Musanze. It's home to the Red Rocks camping and hostel, which, through the Hands of Hope organisation and Amahoro Tours, organises a lively and interesting package of cultural activities open to all. These range from basket-weaving demonstrations (free) to learning how to brew (and yeah okay, drink) banana beer (US$25). Other activities include village walks (US$10), bee keeping (US$30), drumming lessons (US$25) and learning about traditional medicine (US$30).
It's best to arrange all activities in advance through either Red Rocks or Amahoro Tours.