Is it opened today or are renovations still happening

Not sure now ..

Observation deck open

You can go to the tower but restaurant still under construction

The current Renovations do not prevent anyone from going up the tower. Renovations are for the restaurant so going to the form and seeing the great views of Seattle is still a thing you can do. Also there are plenty of places to grab food in the surrounding Park

We visited in October 2017. At that time, the restaurant was under renovation but we could up to the platform which was just below the restaurant.

As far as I know it was always open even under constructions... just partially limited for visit

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