Where in the world can you see WWII U-boats or U-boat pens?

Question

Where in the world can you still see German WWII U-boats or U-boat pens?

Answer 1

Preserved U-boats [1]:

1) Maritime Museum, Bremerhaven, Bremen, Germany

• U-2540 / Wilhelm Bauer, Type XXI scuttled near Flensburg 1945, salvaged 1957, relaunched 1960 as 'Wilhelm Bauer', became museum ship 1984

2) Laboe Naval Museum, near Kiel, Schlweswig-Holstein, Germany

• U-995, type VII-C/41 surrendered 1945 to British at Trondheim, Norway, 1952-1965 became Norwegian submarine Kaura, became museum ship at Laboe 1971
• Laboe Naval Memorial (Marine-Ehrenmal) - Tripadvisor
• thanks to @CarlChristian for posting it in this question about Kiel

3) Birkenhead, Merseyside, UK

• U-534 Type IXC/40 sunk by RAF bomber 1945 in the Kattegat (Denmark), salvaged in 1993 by a Danish team, brought to Birkenhead in 1996, museum since 2009

4) Museum of Science and Industry, Chicago, Illinois, USA

• U-505, Type IXC captured by US Navy, June 4, 1944, renovated and became museum ship in 1954, moved to indoor exhibition hall 2004

5) Finnish submarine Vesikko, Helsinki, Finland

• Type CV-707. Technically originally built for Germany (1933), but operated by Finland 1937-44, not scrapped 1945 unlike the rest of the fleet, renovated as museum piece 1973

U-boat bases:

• The five bases in occupied France were Lorient, Brest, Saint-Nazaire, La Pallice(/La Rochelle), and Bordeaux. Some parts of those pens remain.

Sources:

[1]: AtlasObscura "Remains of the U-Boats’ Watery Reign: The Four Final Iron Coffins", a list of preserved U-boats

• Drawing of all WW2 German Submarine Types(1933-45): https://naval-encyclopedia.com/ww2/germany/u-boats-german-submarines