Complex sentence: Our Lady of Snows Basilica festival celebrated annually during August and the Shiva temple festivals--like Adi Amavasai, Sasti and Chittirai chariot festivals--are the major festivals of the area.
Split into simpler sentences: Our Lady of Snows Basilica festival is celebrated annually during August. This and the Shiva temple festivals, e.g., Adi Amavasai, Sasti, and Chittirai chariot festivals--are the major festivals of the area.