Christiansted is a town on the northern shore of St. Croix that offers some interesting history and some good running options. In town, there are some decent, quieter side streets with several buildings from the Danish colonial era. You can run along those over to Christiansted National Historic Site, which features a marked, self-guided walking tour (~1.5 km) along paths and fields to the Customs House and Fort Christiansvaern.
Another good running option is the Christiansted Bypass — a road leading away from town to a wonderful overlook with great views of beautiful Christiansted Harbor and Gallows Bay. The bypass is 1.9 miles (3 km) one-way, with a steady hill for the second half (grades of 4-5%). There is parking at the top of the overlook, but we recommend parking in town on the lower end so you can gain your elevation at the start, then cruise downhill for a fun 4 miles. Note this is a busy road, almost like a highway, but there’s a good sidewalk. It’s most spectacular on the downhill stretch toward town, due to the views.