Officially opened on Friday, the pavilion is the stage of the Sun & Sea (Marina) opera performance by Rugile Barzdziukaite, Vaiva Grainyte and Lina Lapelyte, the Culture Ministry said.
The audience can view more than 20 performers lying down on 35 tons of sand and singing for eight hours from above.
Visitors are also welcome to join the performers on the artificial beach. They are required to pre-register and bring their bathing suits and towels and lounge on the beach for at least three hours.
The opera performance will take place every Saturday through October.
Lithuania participates in the Venice Biennale for the 11th time. Its pavilion has received four special mentions by the jury.