There are 19 wonderful waymarked trails criss-crossing Andros, marking walks that range in duration from 30 minutes to six hours, labelled in difficulty level from easy to average. Wear hiking boots and trekking pants, as there are some (shy) snakes.
The best investment you can make is the Andros Hiking Map (€6) published by the marvellous Andros Routes (www.androsroutes.gr) project, in conjunction with the Anavasi mapping company. It’s available at bookshops and gift shops on the island. The Andros Routes website outlines the paths they maintain and has good advice for hiking on the island.
Locals recommend the areas north of Hora for great walks, including the villages of Stenies and Apikia. For a lovely short walk, Pithara is a shady glade of streams accessed from Apikia. For a longer ramble, hike up the dramatic Dipotamata Gorge, signposted as you drive inland, after Sineti (southeast of Hora). The trail is cobbled part of the way and leads past ancient bridges and water mills and through vivid foliage, with water burbling below.
Better yet, book a guided walk with Trekking Andros, a company that arranges and guides a menu of activities on the island, including hiking, mountain biking, boat trips, diving, rock climbing and more.