Here's the old port in La Rochelle with two of the three large towers that have guarded the city since the 1300's. The tower not in the photo is just off to the left and is the only surviving lighthouse from the medieval period in all of Europe.
[Fun note: 4 weeks ago a round of the Red Bull Cliff Diving World Series were held in La Rochelle. The divers dove off...you guessed it...the large tower on the right. A small platform was erected on the top and divers plunged to the water below. Take a look at this great promo clip:]