Caesarea is an old Roman port city on the Mediterranean shore about a half-hour south of Haifa. Like many forts and cities in Israel, it has been run and overrun by all sorts of people over the ages, from Romans to Arabs to Crusaders, each adding their own mark to the place.
Pictured at the top of the page is the entrance to the citadel, dating from the Crusades; the smaller pictures are the citadel's moat, also a Crusader addition, and Caesarea's Roman theater, which is still used for plays and concerts today.
You can't visit Caesarea without being awed by the beauty of the Mediterranean. And, in fact, one of the interesting things about Caesarea is that part of it is underwater. If you dive, you can explore the underwater ruins and look at the jellyfish and the occasional pickup truck (how those got a quarter mile out to sea, I have no idea.)
Caesarea was my first scuba-diving experience; I swam along, completely unaware that the divemaster was hanging onto me by the tanks, and wondered why I was having so much trouble steering. Unfortunately, my camera isn't waterproof, so you'll have to take my word about the trucks.
There are lots of barnacle-crusted reefs jutting up out of the water and forming smooth surfaces for the waves to wash over. In the second picture above my friends convinced me to climb a reef (with my bare feet -- ouch!) and strike a pose.
Just outside Caesarea, about a hundred feet from the sea, there's a reasonably intact Roman aqueduct. The aqueduct is actually quite long, extending beyond Haifa; we saw bits and pieces of it at several points in our visit.
UMD Caesarea archaeological dig information