Gili-giliare small islands situated off the beach of Lombok Island. The most popular one is Gili Indah area consisted of three islands namely GiliMeno, GiliTrawangan and Gili Air. GiliTrawangan is a small island with its land consisted of white beach sands sediment from fragments of coral, oyster shells and foraminifera fossils, in both smooth and rough grains. In the southern tip of the island lie lava-structured rocks, composed of basalan and forming a sloping hill with maximum height of 100 m above mean sea level. Pillow lava in the area was formed after hot lava came in touch with sea water.
During the Second World War, Japanese army used islands as observation posts. The remnants from this era include a bunker in GiliTrawangan hill and shipwreck of patrol boat in the depth of 45 meter in a bay south side of Gili Air (now becomes a popular dive site). In this area there are dive centers, hotel, harbor for crossing boat, and traditional mean of transportation (Cidomo) to get around the island.
GiliMeno is a small island about 1.86 km2 width with a spherical salt-water lake. Surface of this island is covered in beach alluvial sediment both smooth and very rough one. In the southern side of the lake lies offshore ground water outlet predicted to be ground water seepage and affect the growth of a unique coral called blue coral. In both gilis local communities and government work together in conserving and improving environmental awareness to protect local ecosystem such as corals, turtle, and other marine life. The area has been declared to become national water conservation area named Taman WisataPerairanGiliMatra(GiliMatra Water Park).