How late will you be in Lisbon? If you can go and see the Fado. Hear is a site that gives a good explanation of the Fado. http://www.golisbon.com/night-life/fado/
You may not have a late enough stay to see a fado. Here is a link to an article about Lisbon Museums. http://www.golisbon.com/museums/
I hope this helps.
Here also is a link to the Lisbon tourism website. This is a link to different routes for walking tours of the city. http://www.atl-turismolisboa.pt/Cont...spx?lang=en-GB