Have to say, had never heard about this lake before. After doing a bit of research i found this:
The Lago di Resia is an artificial reservoir in the west of South Tyrol, to be precise at Curon in Val Venosta. Its striking landmark - a steeple towering from the lake - does not only individuate this lake, but is in fact symbol of the entire valley. Directly at the lakeshore there are the villages of Curon, Resia as well as the hamlets of Casone and Spin.
Up to the year 1950, there were three lakes in this area: Lago di Resia, â€œMitterseeâ€ (also known as Lago di Curon) and Lago della Muta. In 1950, however, when the reservoir was dammed, the locality of Curon as well as much of Resia were flooded and destroyed. The only remnant of old Curon is the steeple, which still towers out of the waters. There are several narrations and sagas around this historical happening and the steeple.
Here is a photo of what the town looked like before it became a lake.