...artificial climbing walls?
 

The two town recreation departments in the area with indoor artificial climbing wall programs, open in the winter, that I know about, are www.meredithnh.org (click on parks & recreation), and www.watervillevalley.org (click on recreation).

Both walls are extremely high quality construction, located in huge beautiful heated gymnasiums, available to children and adults, and pretty reasonably priced. The Meredith wall, aka Mt Meredith is reported to be 24' high and it's my guess that the WV wall is about 20' high. All climbing is done under the supervision by supposedly experienced belayers who know what the heck they are doing to keep this activity safe (I have no clue, but this is hopefully and most likely a safe bet!).

Both public sessions are held on Friday evening throughout the winter, and you can check their websites for time and prices. Saturday at 2-pm; open climb time in Waterville Valley on some Saturdays, too.

As far as I know, there are no other indoor climbing wall programs locally like in Moultonborough, Gilford, Laconia, Wolfeboro, Alton or New Hampton but I could be incorrect?

Wearing loose fitting athletic clothing, and tightly fitting sneakers is the way to dress, and just maybe you can make it all the way to the top .... which is very challenging!

It's a lot of fun. We go to the Nashua and Manchester gyms (Vertical Dreams) often. Give it a try.

Wall in Plymouth
 

I remember NH Chronicle had a segment on that. Are they close?

I think there is one in Dover.

....... Logs of fun?
 

www.logs-of-fun.com at the Weirs Beach roundabout has a climbing wall ....never been in there since the old Dexter Shoe store moved out....but I noticed the sign "climbing wall" yesterday as I was driving around the roundabout looking at that ugly, smooth concrete roundabout apron...and this website has a photo of the climbing wall....pretty good what you can find on the internet......huh?