When I grew up in the heavily farmed Midwest, a beaver dam or lodge was a rarity, an awe-inspiring emblem of wilderness.
But if you pay attention while driving the freeways around here – including those near Boston – you’ll catch a glimpse of a beaver lodge and then recognize the surrounding pond, frequently soon followed by another.
The sight reminds me of a wonderful documentary I once watched on public television. The program followed the life of a beaver colony through an entire year, and then, at the very end of the hour, the camera pulled back from the dam and lodge to reveal a busy limited access highway at the edge of the pond.
It’s enough to make me appreciate both kinds of engineering.
Jnana's Red Barn 
having grown up in the Midwest (Ohio) I feel the same way about beaver lodges. When I visit my in-laws in northern Maine, well, their attitude is different.
BEAVER LODGES!!!