1. The Kalalau trail: experiences the Napali cliff region
Trail Length: 11 mi one round.
Difficulty: Difficult.
Warning: for experienced hikers only
2. The Kukui Trail: goes into Waimea canyon and a big swimming pool at the end
Trail Length: 2.5 mi one round.
Difficulty: Difficult.
Elevation: 2240 ft.
3. Nualolo Trail
Trail Length: 3.8 mi.
Time: approx 3 hrs.
Difficulty: Difficult.
4. The Hanakapiai trail: leads to Hanakapiai Beach
Trail Length: 4 mi round trip from Hanakapi'ai Beach (8 mi round trip from Ke'e Beach)
Difficulty: Difficult.
Warning: this beach is far too dangerous for swimming, and the currents are so powerful that more than one unwary hiker standing in the surf at knee level has been caught up in a sudden and large wave
5. The Mount Nounou Trail, on Sleeping Giant Mountain in Wailua
Trail Length: 3.5 mi roundtrip.
Difficulty: semi-strenuous.
6. The Secret Falls: goes through a tropical jungle
7. The Awaawapuhi Trail: promises sweeping views and a trek through dense jungles and dry landscapes
Trail Length: 6.5 mi.
Difficulty: strenuous.
8. The Nualolo Trail: a good birdwatching place
Trail Length: 7.5 miles round trip or 10.75 miles round trip via Awa'awapuhi loop.
Difficulty: strenuous.
9. The Blue Hole: the best of Wai'ale'ale
Trail Length: 8 mi roundtrip.
Difficulty: moderate.
10. The Kuilau Ridge Trail: for a glorious view of the Makaleha Mountains
Trail Length: 4.5 mi roundtrip.
Difficulty: moderate.
12: Polihale State Park
Source: http://www.hawaii-guide.com/index.php/kauai/list/category/kauai_hiking_trails/
http://kauai.hiking.info/kau_hikes.html
http://www.hawaiitrails.org/island.asp?island=Kauai
http://www.kauaiexplorer.com/hiking_kauai/ has reviews
http://www.tripadvisor.com/ShowUserReviews-g29218-d102945-r4363340-Kalalau_Trail-Kauai_Hawaii.html has reviews
