Exploring Frankfurt’s historic center means you’ll inevitably pass through the Hauptwache—join a walking tour or head to the Hauptwache Café for lunch or a coffee. A medley of architectural styles mark the Hauptwache, including the 17th-century Baroque St Katharina Church, with its 177-foot (54-meter) tall clock tower; the futuristic mirrored façade of the MyZeil shopping mall; and the glass-fronted Zeilgalerie. Beside the Hauptwache café, a sunken terrace area, nicknamed ‘the Hole’ by locals, leads to an underground passageway of shops and eateries, linking the square to the Kaufhof department store.