The bell tower is attached to one of Holland's most famous cathedrals. When you think of old world bell towers you think of narrow passages and stairways and St. John's doesn't disappoint. As you begin your ascent to the top, each floor will reveal another part of the cathedral's evolution from Romanesque to Gothic. Higher up you can also take a look at the intricate system that operates the tower's 68 bells. It seems there's an unending system of wires, ropes, pulleys and countermeasures. Although it's now run by small motors, the system is still impressive and the work that must have gone into running it manually hundreds years ago must have been staggering. Once at the top 43m above the ground you're finally rewarded with a great view of the city. The tour is in Dutch but the whole climb is worth the effort anyway.