Rahmi M. Koç Industrial Museum

The Rahmi M. Koç Industrial Museum (Rahmi M. Koç Müzesi) is a privately run museum founded by the late industrialist Rahmi Koç, set in three buildings on the north shore of the Golden Horn in the Hasköy neighborhood. It's the kind of museum where you say "let's spend an hour" and look up three hours later.

The collection covers transportation and industrial history: steam locomotives, classic American cars (a 1959 Cadillac, a 1932 Ford roadster), biplanes hanging from the ceiling, typewriters, antique sewing machines, and the highlights — a real WWII-era Royal Navy submarine (HMS TCG Uluçalireis, a British-built submarine that served in the Turkish navy from 1944 to 1971) that you can walk through, and a Boeing 727 on the outside deck.

The third building is the best: a fully restored 1930s streetcar you can ride, a science-and-discovery section for kids, and a well-curated section on Turkish industrial history. The terrace has a view of the Süleymaniye across the Golden Horn.

Open Tue-Fri 10:00-17:00, weekends 10:00-19:00, closed Mondays. ~12 EUR. Best for families and anyone who likes machines.