Kütahya is an old western Anatolian city that has been slightly left behind by Turkey's faster routes. That is part of the appeal. The centre still has tiled mosques, Ottoman timber houses, a castle ridge above town, and shops full of the blue-and-white ceramics that made the city famous.
The best part of Kütahya is compact. Start on Germiyan Street, where restored mansions give the old quarter a real shape, then work down to the Great Mosque, the Çini Museum, and the Kütahya Archaeology Museum. The city can feel industrial at the edges, but the historic core is worth the stop.
Two sights give Kütahya more range than an ordinary provincial town. Kütahya Castle climbs above the old town for views across the valley, while the Hungarian House preserves the exile home of Lajos Kossuth, one of the 19th century's great European revolutionaries. If you have a full day, Aizanoi near Çavdarhisar is the prize: a Roman city with one of Anatolia's finest surviving temples.
Kütahya is not polished for international tourism, and that is fine. Come for the tiles, the old streets, and the useful pause between Eskişehir, Afyon, and the Aegean. Stay overnight if you want to see the centre without rushing.