The Western Slovak Museum (Západoslovenské múzeum) is the main regional museum in Trnava, housed in a historic building on the main square. Its collections cover archaeology, natural history, and local cultural history, with particular strength in material from the Roman period — the Danube frontier was not far from here, and Roman remains are plentiful in western Slovakia.
The museum provides useful context for understanding the layered history of the region: Celtic settlements, Roman presence, medieval development, and the period when Trnava was one of the most important cities in the Kingdom of Hungary. The archaeology galleries are the strongest section; the displays are in Slovak but well-labelled with images. Entry is inexpensive.