Hämeenlinna's main sights cluster around the lake shore and the old town. Häme Castle is the centrepiece — one of Finland's finest medieval fortifications, sitting directly on the water. A short distance away, the military museums beside the castle walls cover Finnish artillery history in more detail than most visitors expect. Aulanko Nature Reserve offers the best walking in the region, with a hilltop observation tower overlooking an expanse of lake and forest that stretches to the horizon.
For Sibelius pilgrims, the composer's childhood home on Hallituskatu is a small but well-maintained museum that puts the music in the context of the provincial Finnish city where he grew up.