The Prison Tower claimed to be the oldest building in Neuchâtel with foundations dating back to the…read more10th century. The Prison tower can be found at the base of the Neuchatel castle and is definitely worth a stop for anyone touring the area. Inside the tower as you climb the steep wooden stairs up you will find two two wooden cells that were used until 1848 (couldn't believe how tiny they were!). Once you reach the top, you will find a fantastic view of the city, lake, and surrounding mountains. For only 2 chf entrance free it is definitely worth a visit for the view. The entrance is automated, and there are no humans manning the gate. The tower closes at 6pm. You have to feed the machine exactly 2 CHF in coins, no more, no less. If you don't give it exact change, the door won't open, and you won't get your coins back. We were 10 cents short, and it wouldn't give us back our money, we had to run to a nearby store to get 10 cents to feed into the machine in order for it to let us in. It was quite frustrating. Also, there is a large turnstile gate and a door. It is not the door that you enter it is the claw like turnstile. After you feed the machine 2 chf there is no sound or indication that the door has been released, you just go through. Then the next person is free to feed the machine money. Other than the frustrating entrance turnstile, I enjoyed the view awaiting me at the top.