From the north end of Varenna, you can make a steep half-hour hike up an old mule path to the hillside hamlet of Vezio. It is dominated by the 13th-century Castello di Vezio, once part of a chain of early-warning medieval watchtowers.
From here you can gaze down on the terracotta rooftops of Varenna. The castle also hosts regular falconry displays on Wednesdays (3pm), Fridays (2.15pm), and weekends (3.30pm).