Mt. Hamilton, Columbia River Gorge - This is one of the most exquisite places I have ever been. The views are outstanding, the hike is challenging, and the memories I'll have are unforgettable.
Portland Saturday Market - Wacky, weird, and tons of fun.
Indian Beach - This beach is relatively secluded (there's a $5 entrance fee because it's in Ecola State Park). Totally worth it if you'd like to have a peaceful day on the coast.
Cape Perpetua - Home to several natural wonders like Thor's Well, Cape Perpetua is a beautiful, escape from Portland.