they have a nice museum of trains in Zubrnice in the old trainstation. It is not open all year, but between may and september only. It was a nice excursion for me from Decin, where I stayed in a small private Bed&Breakfasthotel.
The Parish church of the evangelic Bohemian Brethren congregation is located in Decin-Podmokly at the busy Teplicka street (adress is Bezrucova 4, though). It was built on a slightly elevated terrace above the street with stairs leading up to the entrance. Architect was G. L. Möckel, a German architect from neighbouring Saxony who preferred Neo-Romanesque and Neo-Gothic styles - and it shows. Quite typical for the time it was erected - 1884.
The church is not in best shape and the stairs from the street up to the entrance are quite dangerous IMO. Services on Sundays 10 am in summer only. As expected the doors were closed when I visited.
Go by train from Bad Schandau to Decin, The train called 'Beertrain'. Of course, you can drink a lot of beer there.