On Tenney Mtn Hgwy, Rt 93-Exit 26, heading west on Rt 5 toward the west side rotary, you will see the large outdoor selection of landscape rocks, pavers and other interesting outdoor items at
www.3lakeslandscapesupply.com in Plymouth, NH.
It's a big outdoor and indoor place with lots of rocks and other outdoor building items like cut granite and other designs.