Andros, or Andro is the northernmost island of the Greek Cyclades archipelago, approximately 10 km (6 mi) south east of Euboea, and about 3 km (2 mi) north of Tinos. It is nearly 40 km (25 mi) long, and its greatest breadth is 16 km (10 mi). Its surface is for the most part mountainous, with many fruitful and well-watered valleys. The area is 380 km2 (147 sq mi). The largest towns are Andros (town), Gávrio, Bátsi, and Órmos Korthíou.
The island is famous for its Sariza spring at Apoikia where the water comes out of a lionhead. Palaeopolis, the ancient capital, was built into a steep hillside, and its harbor's breakwater can still be seen underwater.
On May 10, 1821, Theophilos Kairis, one of the leading intellectuals of the Greek Revolution, declared the War of Independence by raising the Greek flag at the picturesque cliffside church of St George: at this time, a famous heartfelt speech, or "ritoras" (ρήτορας), inspired shipowners and merchants to contribute funds to build a Greek Navy to combat the Ottomans.