I went to a Flea Market in Esneux, and found a guy selling old postcards of the area.  
This inspired me to look for old pictures on the net, and I found a lot.
Most of these were taken during the Golden Age of Esneux.  
At the turn of the 20th century, Belgium was very prosperous, due to both the heavy industry, mostly in Wallonia, but also due to the infusion of money that the king was bringing in from the Congo.
At that time, Esnuex became a popular vacation spot, and there was lots of building, including the new church and the Chateau le Fy.  
With all the visitors, there were lots of postcards made, many showing the quaint old buildings, the canal, and signs of the new prosperity.
Here are a few, along with what it looks like today.  
         

Hold your mouse over a picture to see what it looks like today
One of the biggest changes in Esneux is the replacement of the old bridge.  On the left you see the masonry bridge that ended right at the Hotel Belle Vue.  We talked with a guy who was a kid when the old bridge was broken down by ice in the coldest winter ever.  He said the authorities came into the school, gathered up all the kids who lived on the other side of the river, and rushed them home in the middle of the day, just before it collapsed.
 
Looking the other way, you can see the other big change:  filling in the canal.  On the left, the lock can be seen in front of the lock house, among the trees.  
All that is gone now, and the left bank is all embanked where it used to be mudflats.
 
This is the other end of the old bridge, and in the new version you get a good view of the Pierced Rock above the river.  I have no idea why it has a hole in it, but it is lit up at night and has a flag flying on it.
 
Looking back at the Chateau, you can see the weir that held the water back where the next leg of the canal branched off.  
Notice the big building on the left that was removed to make way for the new road when the bridge was moved.
 
 
The road into Esneux.
 
Just downstream, there was a lock, and its house, beside the now filled in canal.   The stone work of the old lock gates is still visible in the ground in front of the car.
 
This is the house of the Montefiore family, Rond Chêne, in its heyday, and now.  It's sad to see the elaborate gardens are all gone.

Corner of old Esneux - the new, bumped-out, white store front is our local baker.