If you want to see just how green Oliwa is - or check out the stunning autumn foliage - make your way on foot to this hilltop observation tower in the middle of the woods midway between Oliwa Park and the Zoo. Sitting 100m above sea level, this 15m steel tower has a large platform at the top that puts you over the treeline for great panoramic views of the entire Tri-city. Well worth a look, it's only about a 10min walk from Oliwa Cathedral, but it will certainly give you some exercise.