Look out from the floor the shots were fired from
The corner window, preserved behind glass
A working warehouse floor turned exhibition, tracing the presidency, the motorcade and the investigation, with the south-east corner window left as it was found.
Why it's unique
The museum occupies the sixth floor of the former Texas School Book Depository, and the corner sniper's nest is preserved behind glass with the book cartons rebuilt to match the police photographs taken that afternoon.
It is the room rather than a reconstruction of it, on the floor it happened on, looking down onto the plaza it happened in. There is no second version of that anywhere.
Before you go
Take the audio guide; it is included and it is unusually good, built largely from contemporary broadcast recordings and eyewitness interviews rather than written narration. Photography is not allowed inside.
Afterwards go down into the plaza and find the two white X marks painted on Elm Street. They are unofficial, repainted by locals when the city removes them, and standing at them is what makes the geometry from the window make sense.