Andros 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. Its surface is for the most part mountainous, with many fruitful and well-watered valleys. The largest towns are Andros (town), Gavrio, Batsi, and Ormos Korthiou.
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 the breakwater of its harbor can still be seen underwater.