The historic Hulda Klager Lilac Gardens in Woodland, WA (about 30 minutes north of Portland, OR) are open from 10am-4pm daily.
Now is a great time to go, as the lilacs are coming into bloom and during “Lilac Days” (April 16 through May 8) plants are for sale, too!
$3 admission. Free for kids. No pets.
For more info: http://www.lilacgardens.com/