Kauai is a stunningly beautiful Hawaiian Island with an abundance of amazing natural resources to see and lots of fun things to do.  

Here are some of my own personal recommendations:

Steelgrass Farms Chocolate Tour: See history in the making.  Hawaii is the only US State that can grow the cacao bean, and there's a small movement towards using some of Kauai's agricultural lands to build a cottage chocolate industry.   Steelgrass offers a tour of the farm, and a double blind chocolate tasting.  Heavenly.  

Waimea Canyon: Kauai has it's own Grand Canyon that can be entered from the northwest side of the island.  It's truly spectacular.  

Na Pali Coast:  Stunning.  You can not drive to Na Pali.  You have to get there by foot, boat, or you can view by helicopter.

Friday Nights in Hanapepe Town:  Good street food, live music, the galleries are open late (well....until 9:00.)  You can also make reservations to dine at the Hanapepe Cafe: (808) 335-5011 which is only open on Fridays from 5-9.  Really fun, and a great way to support local talent.  Visit the Talk Story Book Store.  The western-most book store in the USA.

First Saturday Old Town Kapaa Art Walk:  It's really a big street party.  Held only on the first Saturday of the month.  There's dancing, antique cars, street food.  Very popular.

Kayaking in Hanalei: There might be other businesses that provide this tour. It starts as a tranquil trip through a small Hanalei river.  After you get your sea legs, the tours heads into the ocean, stops at a snorkel beach for lunch and then heads back.  Really really fun!

Kauai Hindu Monastery: Some of the most spectacular scenery on the island is located within the grounds of this Monastery.  Plan your visit a head of time and take the guided tour.  Don't just show up.  Quite often they have private retreats, and you won't be allowed to walk around.  It's also very important to bring bug repellant and to wear the proper attire when you visit.  

Farmers Market:  There is a farmers market everyone day on Kauai.  The locally grown food is so much better than what is sold in the supermarkets.  Try the apple bananas.  My personal favs are the 9:30 am Saturday morning in Hanalei and the 3:00 pm Wednesday afternoon in Kapa'a town.

National Tropical Botanical Garden:  I realize I could lose all credibility by listing a botanical garden, but this one is mind blowing.  Book in advance and take part in the Allerton Garden guided tour and you will not be sorry.  Plus, it's right across the way from Spouting Horn.  A win win.  If you are truly a planner, you can do the tour on a Friday afternoon, and then head over to the Hanapepe Art Walk afterwards for a dinner of local street food (try the savory pies), and the local visual and performing art.  This could make for an amazing day.

Hanalei Strings: Every Tuesday night is "Knit and Pick."   Beginning Ukulele lessons at 6:00pm - no experience necessary and they will provide you with an uke.  There is a multi instrumental jam session to follow.  You can also learn to knit.  A string shop in the truest sense.  Hanalei Strings is becoming one of the cultural musical centers on the island.  Be sure to check their Facebook Page for upcoming shows.  Kauai has some amazing local talent.