William from Tacoma here so I will recommend Point Defiance and Ruston Point here in Tacoma. The Point is the second biggest Municipal (in a city) park in country second to Central park and has a beautiful rose garden, its on the water and also a zoo and aquarium. Not far is Ruston Point is new and features on the water eating and shopping, walking and is nice and kinda posh. - Also if you are coming up here and like history, mystery, beer and food there is a chain of Restaurants called McMenamins all over Portland and in some of WA including the new Elks Temple in Tacoma. They take old historic properties and restore them, make great beer and each property has lots of art, history and surprises. I highly recommend the Edgefield 15 minutes outside Portland along the Columbia. Look into doing a scavenger hunt there. - Also recommend Boeing Museum of Flight in Seattle, Washington Park in Portland and the Japanese Garden therein. Pearl District and Alphabet shopping and restaurant districts in Portland. McMenamins everywhere in Portland (seek the cajun tots), also the Deschutes Brewery (Pearl) and Food Trucks up over the burnside are fun. I’m not in love with Downtown Seattle after working there for many years but visiting Seattle Center is interesting as it was the location of the Worlds Fair back in the day, I’m sure others will have good recos for that area. One more thing is there is a Lego store towards Beaverton OR for tax free Lego - Have a good trip up here!