Bursa is better understood if you live there or stay longer then normal touristic trips.
For short visits, I would recommend the lonely traveller to discover the bazaars located between the "Ulucami" mosque and "Cumhuriyet caddesi" street. Bursa, being an ancient capitol of silk has still reputation and capacity in textiles... Watching the crowds and the oriental atmosphere in the bazaars could be a new experience for you...
For those who intend to stay longer, Mosques (all are very old) could be visited; better in non-prayer times. Just walk in taking your shoes off (watch the local guys). Ladies must wear long skirts or trousers and a head cuff not to confuse mosque inhabitants, if you are with a miniskirt there is usually a "long skirt service" in the mosque- just ask, and then walk in with shoes in your hand and sit in a corner.. enjoy the silence, watch the ancient architecture, caligraphy and feel the prayers of the souls flying around and listen to yourself...
The photo shows the inside of "Ulucami" mosque built 1399 AD.
**will tell more about BURSA later.