What is there to do off the 5 freeway between Los Angeles and Seattle?

I am driving from LA to Seattle and wanted to know what interesting things and places there are to see along the way. So far I have found the Sundial Bridge in Redding, which looks very interesting. I am a 23 year old college student with an interest in architecture.What is there to do off the 5 freeway between Los Angeles and Seattle?
I have done that drive a millon times. There really isnt a whole lot to see. From the grapevine to Sacramento is hell. Northern cal and Southern Oregon is beautiful! The trees, mountains, Lake Shasta. From about Eugene to Portland sucks also. Boring and straight. Portland has some cool gondalas that go over the freeway and some great bridges. Enjoy the trip! I did it already once this year and doing it again in 6 weeks :)What is there to do off the 5 freeway between Los Angeles and Seattle?
San Francisco and the Redwoods are on the way.