Just join some NGO and be a part of good cause. Do something serious for the sake of others. It may be planting few trees, cleaning some sources of drinking water, educating some poor children or something like that. You will feel much more pleasure deep inside your heart than doing some fun oriented things. You may vote up if you like my view.
For a vacation, I would encourage taking in art and culture, or the beauties of nature - filling the well, so our creativity is nourished.
I'm also a big believer in retreats. Like vacations, we go away from home. But instead of focusing on travel or distraction, we can focus on either introspection or creativity. Meditation retreats are wonderful, and writer's retreats and artists retreats are great, as well.
Develop your spiritual growth though attending church activities and fellowships. You can also do the vacation on the far away distance from the city which is filled with nature beauty. All you need to bring is your Bible in order to read and understand the word of God. In this way, you can feel very safe, peaceful and mostly being close to God. As of me, this is the best thing that I will do in my vacation time.