We just got back from a whirlwind trip of Austria, Hungary & Slovakia. We stayed 2 nights in the spa town Trenčianske Teplice to watch our DD's orchestra concert. It was difficult finding info. about how to get here and had to wing it. Now that we've successfully done it, here's some info. on Trenčianske Tepla (TPA), Trenčianske Teplice (TT), & Trenčin.
We took the train from Šturovo up to TPA, transferring in Bratislava. TPA is a small, but very clean, nice station. Bathroom attendant keeps WCs sparkling. (€0.40)
Not sure how we would get to TT on arrival, but lucked out that it was on a Slovakian holiday. I knew from YouTube videos in Slovakian that there could be an electric tourist train going to TT, and there was! I think it runs in the summer and at Christmas. Had to wait 40 minutes or so, but it was very cute with lots of excited little kids on it. You buy the ticket on the train, not at the station for €1.50. Felt like we were on a Thomas Tank Engine ride. Train attendant sells little souvenirs after the ride.
Unfortunately, I don't have a schedule for this train, but I don't think it runs that frequently. We couldn't take it back down because the first one going back from TT to TPA on a Sunday was at 11:00 which was too late. I will reply post about alternatives. Glad we did it, but not sure I would count on it to get to TT without better info.