If you are looking for great site seeing close to Spangdahlem Air Force base, we have found a great castle about 30 minutes from base. It's called the Manderscheid castle.
This castle was built in 1427 and is gorgeous! It's very affordable and children under 6 are free. Each adult is 2 euro, and children 6 and over are 0,70 euro. It's family friendly with beverages for purchase at the entrance with a little gift shop and bathrooms. You may also buy an English brochure on the castle for 0,50 euro.
At the end of August there is supposed to be a huge medieval festival with games, food, and crafts and jousting shows, etc. Also, there is a huge fireworks display on the Saturday night of the festival. This year it is on august 24th and 25th, 2013.
Here is their website
The castle is great to explore and my 3 year old was able to climb everywhere we wanted to go with some assistance. It's not great for strollers and is better for older children or infants you can carry during the visit. It takes at least 2 hours to walk around to every area of the main castle to appreciate the beauty of it all.
It's a great site to see and will be one to take visiting family to as well. It's cheap, close, and really beautiful!
Type in your GPS Manderscheid (zip- 54531) Grafenstrasse 23 to find the castle
Here is a link from mapquest from Spangdahlem AFB to the castle