One of the best places to experience this somewhat unusual site is the small German town of Unteruhldingen on Lake Constance, not far from Friedrichshafen and Konstanz. It features a well-known open-air museum with reconstructed pile dwellings and an interesting exhibition. Of course, the museum itself is not part of the WHs, but there is probably no other place where the mysterious, prehistoric world of pile dwellers is so graphically illustrated. And there is an actual WH location near the town's port, maybe a 5-minute walk from the museum. You can only see the plaque on the shore, as the pile dwellings are underwater and also covered by a canvas to protect them from damage caused by weather or boats. Still, it is good enough to tick off the site. Unteruhldingen is next to the famous flower island of Mainau, and can be easily reached by ferry from Meersburg.

On a trip to Zurich, I checked out the 2 sites on Lake Zurich in the city centre, but couldn't find any sign. I also went to Rapperswil on the southern end of the lake and tried to find the sites there, but only found general signage, not specific pointers (but the area seemed perfect for pile dwellings, especially along the footbridge connecting the town with the island of Hurden).