We flew from San Jose to San Juan via Dallas. Puerto Rico is part of the United States but isn't a state so their citizens are American but can't vote. It's been fought over by the British, Dutch and Spanish because of it's strategic position in the the Caribbean. There are two forts at each end of Old San Juan and some of the 20ft thick walls still survive. Lots of cobblestone streets and colourful colonial houses make it attractive (apart from the ridiculous amount of traffic).
I'd found a privately owned apartment in the old part of town and it was very convenient for walking to lots of restaurants and historic sights. We had two whole days before the cruise so we rented a car for a day and drove south to Ponce. The road system is fairly chaotic and although you're supposed to be following American rules of the road, the signs are in Spanish, the speed limits are in miles but buying petrol is in litres. Using the hard shoulder to overtake is common!
Ponce city centre is quite pretty and has a very brightly painted fire station - red and black stripes. We went to visit Don Q's house, an old family run rum producer, which looked out over the coast.
We we arrived back from the cruise we spent another two nights in the apartment. We did a couple of day trips to Arecibo to visit the largest radio dish and El Yunque rain forest which is an hour from San Juan.