A popular tourist attraction on St. Lucia near the south on the island is the drive-in volcano, purportedly the world's only! It's interesting enough but better like the smell of sulphur which is quite strong. The only down side are the hordes of vendors who accost every tourist trying to sell trinkets.
Unique Suggestions: Learn to say "no" and mean it!
Fun Alternatives: If you go in a group on a group tour the guide can be helpful in fending off the vendors.
Castries is a ghost town on evenings and at week-ends.
If you are looking for action find yourself up north in Rodney Bay, on a Friday choose between Gros Islet or Anse le Raye.
The 'liming' in this island is from Wedesday to Sunday and peaks on the Friday.
Climbing the piton was a great adventure, but the view from the top was not what you would expect.
The rainforest hike we took also was a rip off. The trail was new and unless you like seeing a variety of trees, there's not much else to see.
Don't rent a car and have someone drive you around the island. It's easier to drive yourself but make sure you have a map! The road back to the hotel (there was only 1) was under construction and we had to turn around and go another way taking an extra 2 hrs to get back. The roads are very curvy and difficult, especially if you are prone to motion sickness.
Okay, it was a touristy thing to do, but we couldn't resist taking a boat ride on the Brig Unicorn--an old fashioned, pirate-style boat that was used in the filming of 'Roots.' A more mellow version of a booze cruise, we sailed down the western coast of the island with great views of Pigeon Island, Marigot Bay, the Pitons and a stop at Soufriere. On the return trip back to Rodney Bay, we stopped at a cove where we could take a dip into the blue-green waters (either via ladder or swing). With Bob Marley and soca music playing in the background, rum punch flowing, and a cool ocean breeze, tourist trap or not, we indulged and had a wonderful time!