There are three harvests which are known as the "Unduan-Kesongo", "Unduan-Telor" and "Unduan-Kepat", and take place in April, the latter part of August (the largest), and December. The places Rongkob and along the south coast of central Java are famous for the edible bird's nests, made by the little sea swallows (so called, but actually swiftlets), called "Salanganen" or "Collocalia fuciphaga". The harvests are famous because of the wayang performances which are held, and the Javanese ritual dances which are performed with gamelan music as the traditional ceremony.