Odalan is a temple anniversary, according to the lunar Balinese calendar (210 days). On this occasion, there are 3 day festivities, including praying ceremonies, processions, when deities are paraded from one temple to another, and dancing on the temple’s courtyards.
People staying on touristic areas will mostly be unaware on the dimensions of these festivities.
For example, the images shown below, are from a ceremony in Muntig, a small village, a few km uphill from some of the most popular macro dive sites in Tulamben area (Seraya secrets and Batu Niti). Despite living in the area for some years, now, I was surprise by the numbers of people attending and taking part on it.
I went to a few ceremonies, including Odalan, near Tulamben. Find them in here: