I was thinking about this thread and considering where I'd want to take my own children.

I think my top choices would be:

Tokyo Edo Open Air Museum
http://metropolis.co.jp/tokyo/497/art.asp

and

the wonderful Nihon Minka En
http://www.city.kawasaki.jp/88/88minka/home/minka_e.htm
It's possible to go inside many of the houses here - the woodfire smells of the iriori (cooking pit) are embedded into the beams. Look for a strange bamboo made cage that served as a rudimentary cable car to haul people over ravines and japanese sandals for ice skating. The whole place is in a wonderful parkland setting.


One last tip.



Can I strongly urge anybody going to Japan with children to get them a good notebook with plain paper - it will need to be at least A5 size.

At almost every location there will be, somewhere, a rubber stamp and inkpad for you to take a souvenir impression. Even train and subways stations have them (the one at Ryogoku is especially nice!). Stamps are free. It's often quite fun to locate them.
More info and examples here:
http://www.dotpattern.com/artwerk/ru...er-stamps.html
and here:
http://www.dotpattern.com/artwerk/ru...r-stamps2.html

Ask for "Stamp Rally" (Sutampo Rarri) and show your book (hopefully with some already in there) if you need help finding them.

As an example, they are dotted all around the Nihon Minka En and are in little houses like this one: http://www.pref.nara.jp/narakoen/sr-2.JPG

Stamp Rallies are part of the culture in Japan and are often used for promotional purposes - here's a photo diary of some children who went on a special event train journey themed on Anpan Man - a popular cartoon character. It shows the stamps they collected in their commemorative booklets.
http://ww82.tiki.ne.jp/~mchome/stamp...003_5_17_3.htm
(makes you feel sorry for any commuters caught on one of these whilst nursing a hangover - no wonder one of the stations is called Gomen)

Of course, you don't have to be a child to collect the stamps. There are some truly gorgeous ones around (my favourite is one from Tsukiji tourist information office). Temples have them, all the museums do, sometimes shops have them... you find them in the strangest places.

I first found out about them on my first trip to Tokyo when a couple of German psychiatrists who were staying in the same hostel as I was showed me their own collection - they'd been travelling throughout Japan staying mainly at Temple lodging. The books they'd made up were beautiful.

Happy hunting!!!