One of the neatest places we visited here in Portugal is a village called Obidos. Obidos is a very old town, dating back hundreds of years. The entire town is surrounded by a huge, thick wall which was constructed in order to protect the people from invaders.
There is only one way in and out of the town, and that is it, shown above. See how narrow the entrance way is? It is shocking to see the trucks and cars drive through there! When you come out of that entrance way into the town, it is just beautiful! There is a church, the castle, and many little back roads with cute little shops and houses.
My husband and daughter decided to walk around the perimeter of the city, on top of the wall that surrounds it. Now, you must understand how high up this wall is! It is hard to see from the above photo, but this wall is probably at least 50 feet tall and 2 or 3 feet thick! I am not a fan of tall places, so they went on their own, and the entire time they were gone, I was praying aloud for their safety. There is absolutely no railing, and some of the sections of the wall are only about 1 foot wide.
But as you can see, the view is just priceless...