Saint Croix is the largest (82 square miles) island of the U.S. Virgin Islands, a territory of the United States of America. This formerly volcanic island of spectacular beaches and mountains, rainforest, palm trees, and historic towns.

There are two towns on the island:

• Christiansted 
• Frederiksted

Mainlanders may be a bit shocked to find that even in a territory where the GDP per capita is 60% lower than the mainland, prices are about 20% higher than in a mid-size city like Boston. Don't worry - you're not being taken advantage of just because you're a tourist. The island generates all its electricity from oil, which also powers water treatment plants. Utility costs are thus very high, and many goods must be transported from the mainland. Even though there is a lot of beautiful open space, the supply of practical real estate is limited and thus rents are also high.

Christiansted

and

Frederiksted

have narrow roads and closely spaced historic buildings showcasing historic colonial Danish architecture. How often do you see a sidewalk that goes underneath the second floor? Many buildings have no windows, but only the traditional wooden shutters which completely cover the opening when closed. Window shopping on St. Croix is thus generally not possible; it is necessary to visit shops when they are open. Given its small population, most shops in Frederiksted have short hours and many only seem to open when a cruise ship is docked. However, there are stretches of the gorgeous public beach very close to the town center. Christiansted is slightly more lively; it has no beachfront but does have an active boardwalk and marina area.
There is a mural in the Cruzan Rum Factory showing two types of people - those who live in the big city who are always busy running around, talking on cell phones; and those who live on the island, taking it slow and relaxing. If you are the kind of person who will get bored just sitting on the beach all day, St. Croix is probably not for you. Plenty of men can be seen lounging in the sun around town. Maybe it's the unemployment rate, or maybe it's just the pace of life in the Caribbean.
Many businesses operate on "island time" - slowly. For example, at about half of the fine dining restaurants on the island, service takes what feels to most outsiders like an inordinately long time; the other half is comparable to the mainland. There are definitely culinary gems in Cane Bay and Christiansted; if you are staying elsewhere on the island, you'll probably want a car to get to a well-rated establishment or to the grocery store.
The urban areas of the island can be completely explored in a few hours - big city types used to roaming the urban jungle will instead have to make due with actual jungle. Anyone fascinated with ruins will have a lot to look at one the island. Even on the main commercial streets in town, there are buildings experiencing severe neglect or abandonment. The remnants of several, probably destroyed by one of the many hurricanes that have blown through the island, are filled with trees. There are also a number of colonial Danish stone sugar mills dotting the island, part of St. Croix's plantation legacy.
The flatlands south of Route 70 are partly industrial, with the airport and the Hovensa oil facility. Also on 70 are the University of the Virgin Islands and the agricultural fairgrounds. Covered in exhaust towers and the size of a large central business district, Hovensa operated as a refinery until 2012, when operations were severely curtailed and it became a storage-only facility. The refinery provided 20% of the entire territory's GDP, so its closure has provoked a major economic crisis for St. Croix and the territorial government on top of the effects of the Great Recession. UVI and a stimulus-funded broadband initiative are attempting to stimulate the economy with high-tech training and infrastructure.
The prevailing winds are from east to west. This puts the southwest of the island, including Frederiksted and western beaches downwind of the Cruzan Rum Factory and occasionally unpleasant odors from the open-air fermentation tanks. Also watch out for prickly nettles on the beach between Frederiksted and the turtle sanctuary. On the other hand, the beach here is spectacular, with gorgeous blue-green waters, Caribbean sunsets, a view of the mountains and cruise ship dock, good snorkeling, and plenty of white sand. Often groups of locals will set up enormous speakers, pound the beach with popular and island music and have a barbeque.
The spectacularly hilly rain forest is in the northwest and is a full-on jungle complete with vines and some 4x4-only roads. North of the mountains from most of the island, the well-sheltered Cane Bay also has spectacular snorkeling, with abundant coral, fish, and even some sea turtles in the deeper water. The East End is somewhat remote, though it is dotted with luxury homes on frighteningly steep roads. This end of the island gets less rain; the general lack of trees highlights the spectacular topography and provides an unobstructed ocean view. And where else can you see a Very Long Baseline Array radio telescope across the street from a gorgeous beach?
St. Croix is a bit behind the mainland in terms of finding businesses online or in a phone book, but it's easy to find restaurants on Yelp.