I was lucky enough to be in Japan in 1999 and 2001 and visit some of the top sword viewing places in the country.
Here are some of the places, and how to get there:
Okayama-City
Osafune (Okayama prefecture)
Osafune (again in 2001)
Tokyo
Shiogama (Miyagi prefecture)
My book Nihonto collection can be viewed here.
Information about Nodachi.