Here with images from a recent visit to the Museum of Science and Industry U-Boat exhibit. The U-505.
The U-505 a National Historic Site. German submarine as captured by the U.S. Navy in 1944 on the high seas. Since 1954 a permanent exhibit at the Museum and only recently  moved to the underground exhibit hall.
If you are in the Chicago, Illinois, USA area I recommend a visit to the Museum and the submarine exhibit without qualification or reservation. Impressive!! For a nominal cost there is a walk-through of the U-Boat, this too is a must!!
An amazing engineering feat the construction of the underground two level exhibit hall AND the movement and lowering of the submarine into final position. This video shows it all and is well worth watching. About three hundred pounds [136 kilos] of rust removed and meticulous attention to detail during the renovation process all to fruition, no expense spared I might assume. Total cost for the brand-new exhibit hall and movement about $24 million USD.
From the upper level of the exhibit hall. This is the submarine pen at Lorient France. NO, only built to resemble same. Looking at the boat from bow toward the stern. Length of the submarine is nearly seventy  meters or about two hundred thirty feet. A Type IXC U-Boat more or less intact.
From the stern looking toward the entry point of the exhibit hall. U-505 had two propellers, two rudders, two rear diving planes.
Conning tower of the U-505. Actual battle damage is visible on the right side where the tower meets the deck. The ship had [?] a four inch [105 mm] deck gun and two AAA positions, one apparently 40 mm and the other a 20 mm gun. Doenitz at some point gave the order for his crews to fight it out on the surface with attacking allied warplanes. But that tactic was not successful.
Torpedo los!! Actual full sized torpedo as having been fired! That man in the lower right of the image gives you some indication of the scale.
View from inside the control room. Lighting inside the ship kept at a level as it would be during a combat mission. NO gimmicks or replicas here. This is the real stuff. The ship nearly able to take to the water.
Another view from inside the control room. That ladder and hatch leads to the conning tower. And no, you cannot ascend, those bars are there for a reason!
Passage way from the control room aft. Meticulous attention to detail during renovation evident.
Engine room of the U-505. Monstrous sized diesel engines as used during surface running. Submarines of the WW2 era predominantly operating on the surface, submerging only as necessitated.
Hatch way leading to the rear torpedo room. Crew slept with their weapons.
This is a piston with connecting rod from one of the diesel engines. From top of the piston to the bottom of the connection rod that is one and one half [1 1/2] meters. About five feet. At least one of the engines in the U-Boat is fired up from time to time!
Beware that at certain times of the year you might encounter large crowds. Plan your trip carefully and reserve at the museum web site a time for the internal tour of the boat. Consider too that the U-505 exhibit as a mini-museum within a museum. That Museum of Science and Industry even much more and all worth viewing.