We hired a taxi driver to give us a 4-hour tour of the island. Several key sightseeing locations were closed because of the "Three Kings" holiday, unfortunately. For example, the Cruzan Rum distillery. But we had a great time anyway. Our driver, Joseph, was a veritable encyclopedia of facts and figures about the island.
Two highlights were Point Udall and the Botanical Garden. Point Udall is the easternmost point of land in the US. Standing there at dawn, you would be the first person to see the sunrise. A monument was erected there in honor of the new millenium, and dedicated on New Year's Day, 2000.
The botanical garden is placed in the ruins of an old plantation. You can still see several intact slave houses, a blacksmith shop, etc. The plants are native Caribbean species, and there is quite a variety. I was particularly impressed with the collection of cacti and succulents. Some really large and interesting plants, several in bloom.
We also stopped briefly at the site where Christopher Columbus landed on St. Croix in 1493. The park service has some ambitious plans for this site, but at the moment there is just a small sign.