Here's some pics I took in a canal that runs through my city. Went at night to avoid being seen, but some people still saw us and just didn't care. Tried going into a tunnel that goes under a freeway, but abandoned that plan when a homeless man's dog started barking at us from inside the tunnel.
This tunnel goes under a strip mall.
And here's where the canal splits into two canals. The above pictures are from further down the right branch.