Here I am in my mid 70s and I always thought robins built their nest in trees - This year I have one in between a couple of roofs, down at the town office they have one on the porch and Cathy Thayer sent me this one that definitely isn't in a tree:
(http://www.vtgrandpa.com/photos/albums/Fairfax-Wild-Life/ctrobins_080518.jpg)
Thanks Cathy