Nyepi is the Balinese Hindu Day of Silence — possibly the most extraordinary national holiday in the world. The entire island of Bali shuts down for 24 hours: no flights, no traffic, no lights, no noise. The airport closes. Residents and visitors alike stay indoors or in their hotels. The streets of what is normally one of the most hectic tourist destinations in Southeast Asia fall completely silent. Stars are visible that are invisible every other night of the year. The day before, the Ngrupuk parade features enormous ogoh-ogoh monster effigies processed through every village before being burned.
The Ngrupuk parade the evening before Nyepi — visiting different villages to see the ogoh-ogoh — is the most visually spectacular part for visitors. During Nyepi itself, stay in your hotel and embrace the silence: it's genuinely profound.