Megan C.
Yelp
Christiansvaern is the old giant yellow fort along the water in Christiansted. It's only a few dollars of an entrance fee and is well worth your time, if you enjoy history or historical architecture.
For history or museum buffs: There's a lot of placards inside, from a timeline of the history of St. Croix, to a room explaining the background of Alexander Hamilton (one of the more famous former residents of St. Croix). The fort still has the old kitchen up, soldier's quarters, privy, as well as the dungeons that imprisoned rebelling slaves. The placards seem mostly historically accurate, with only some minor fact or grammar errors, and they don't necessarily skimp on the poor realities women and African slaves faced back in colonial America. The top level of the fort still has the old cannons and cannonballs there, dating back to the late 1700s/early 1800s, but the explanation signs and placards are heavily damaged in these outdoor areas and are near illegible.
For historical architecture interests: you can wander around pretty much everywhere in the fort, with beautiful views to the bay and understand the strategic significance of this site. You see the different levels and room utilizations, from the average soldier to the colonial officers. The clean lines, colonial structures, and yellow paint make Christiansvaern an architecturally beautiful site.