Altona is an upscale borough that includes the neighborhood of the same name, known for a boisterous Sunday market inside the glass-roofed, 19th-century Fish Auction Hall. The Soviet U-434 Submarine is now a museum and Altonaer Balkon park offers harbor views. Elegant Blankenese has half-timbered fishermen’s houses and pre-war villas, as well as the winding steps of the Treppenviertel area, leading up Süllberg hill.