There isn't an awful lot to do in Devin except for enjoying the mineral baths and the spa treatments.
A small museum showing the works of local artists is located in the centre, but I didn't visit it.
If you're into hiking there are small trails into the mountains.
St. Ivan Rilski Church is considered to be one of the places of interest in Devin. I have not been inside of the church, nor I spoke with somebody from the church, so I can not say much about it.
The church is relatively new. It was built in 1937. I suspect that it probably means that there are no fine murals and worth-seeing icons.
What you see on the picture is Devin's history museum. It is easy to find, right in the center, opposite the house of culture. There are signs around the town directing you to the museum.
I tried to visit it but while I was there it was closed. I am not sure if it was closed because of the working hours or because the building is still being renovated. The renovation of the building is part of the Beautiful Bulgaria project sponsored by PHARE program.
I had been told that in the museum you will learn some things about the history of the town and see an ethnographic collection.
Since Devin is not exactly full of sightseeing spots I think this could be considered as one of the local places of interest :)))
If you click to enlarge the picture you will see that the building of Devin municipality is hosting not only the Devin municipality administration but also a cafe, a place for placing bets on football games and on the top of all a night club. :)
This kind of multifuctionality is the living example of how open-minded Bulgarian people are. Obviosly the mayor sees nothing wrong to have a gambling spot, a night club and municipality administration under the same roof :)))