You can swim at Karavostasi, or get a caique (10€ round-trip) to the island's best beach, Katergo, which is protected from the sometimes-fierce winds here by rocky headlands. You can also get by caique to Angali, the largest and most crowded fine-sand beach on the island. There are a few tavernas on the beach and rooms to let.
The footpaths through the northern part of the island, for the most part, are well used and easy to follow. Numerous paths branch off to the southwest from the paved road through Ano Meria; the hills traversed by these trails, between the road and the sea, are particularly beautiful. Here's one walk you may enjoy; if you want to try more walks, check with someone at the Sottovento Travel agency for tips. There may even be a walker's map by the time you visit.
Ayios Andreas to Ayios Yeoryios -- An easy path leads you from Ayios Andreas to the bay at Ayios Yeoryios. Take the bus to the next-to-last stop, at the northern end of Ano Meria; it will let you off by the church of Ayios Andreas. At the stop, the sign AG. GEORGIOS 1.5 points to the right. Follow the sign, and continue along a road that quickly becomes a path and descends steeply toward the bay. Follow the main path at each of several intersections; you'll be able to see the bay for the last 20 minutes of the walk. You'll find a small pebble beach at the bay of Ayios Yeoryios, but no fresh water, so be sure to bring plenty. Allow 2 hours for the round-trip.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.