[johnElarue]

Your husband must be a real history buff. Go to Izushi 出石　for soba afterwards, it is quaint , a little touristy, like a small Kyoto. It is about 30 minutes north. See the clock tower and castle.
Not much around Takeda itself, but there is Tataragi art museum in Asago, 15 minutes south, and Ginzanko silver mine in Ikuno, 30 min. south.

You can do or watch paragliding, grass skiing at Kannabe Kogen about 50 minutes northwest. Lots of camping and cottages also. The Uemura Naomi museum is interesting. 天滝　falls in Oya is nice , but is a short hike. I recommend going to the sea, about 1.5hrs north. Kinosaki onsen is famous, Takeno snorkeling center(2hrs), where you can rent kayaks and swim if the jellyfish havent started yet. And drive the Sanin Coast road west to Kasumi(2.5hrs) it is dotted with beaches but you have to explore a little. Or drive east from Kinosaki, towards Kyoto pref. and go to Amanohashidate, highly recommended. It is about 2.5 hrs from Takeda. There's more stuff in the mountains if you are interested. とのみね　高原　 (1hr) south has a festival in Sept.

You are smart taking vacation after the crowds.