Zytturm
The clock in this watchtower is held up by two frescoed giants. It was made in Basel in 1535 and still keeps time, as visitors can bear witness in the viewing gallery onto the heavy stone weights and pendulum. The Zytturm houses a series of other regional, historic clocks, and is one of four towers along the city wall that are open to the public from April to November. It's a narrow, steep climb, but the views from the top, across the city to the Alps, make the effort worthwhile.