Antiparos (anc. Oliarus or Olearus), an island of the Grecian archipelago, one of the Cyclades, forming part of the eparchy of Naxos, Greece, about 3 by 7 m., separated from Paros by a strait 1 1/2 m. wide; pop. about 1,000. Cotton, barley, and wine are produced in small quantities. The island contains masses of white marble, and is celebrated for a grotto, 120 yards long, 113 wide, and 60 feet high, situated 2 m. from the sea, at an elevation of 500 feet. It consists of an immense marble arch, the roof, sides, and centre of which are covered with stalactites and dazzling crystallizations assuming the shapes of columns, screens, flowers, trees, etc. The stalactites hanging from the roof unite in several places with stalagmites rising from the floor, so that the arch is apparently supported by a continuous series of pillars. The grotto is entered by a natural arch of rugged rock, overhung with trailing plants.