Ranked in no particular order, here's the list of must-do things if you are in Kauaʻi.

Boat-ride to Nā Pali Coast

Located in the northwest side of Kauaʻi, Nā Pali Coast is one of the best things to see on this island. Rugged cliffs that rise four thousand feet high along the shoreline make a gorgeous view. These cliffs enclose the lush Kalalau Valley - which was once home to native Polynesians.
We booked a four hour boat-ride to see this coast (which is inaccessible via road). Over the course of the boat-ride we saw a lot of ocean life. This includes flying fish, whales, spinner dolphins and the endangered Hawaiian green sea turtle. My favorite were the dolphins, of course.

This boat ride was 115$ per person (breakfast & lunch included), and we also had a forty five min stop-over for snorkeling. Worth the cost, must-do!

Snorkeling in Poipu Beach

The most unique thing about Poipu was that you could go to the snorkeling area immediately. The reef was very close to the shore, and you could see fishes and marine life in less than a minute under water. This was the first time I also saw a snake eel. The second time at Poipu, we saw three endangered Hawaiian monk seals coming up on the shore to relax and sleep. We got lucky!

Poipu beach is in the touristy area, so do not expect to get the beach all to yourself. But if you forgot to pack something essential like sunscreen, you can buy it at the store located next to the beach. All in all - great beach, must-do if you're in Kauai.
ps. There are other beaches like Lydgate beach and Ke'e beach - which are also good for beginner and advanced snorkeling. My favorite was Poipu.

Hanakapi'ai Beach hike

For the best views in entire Kauaʻi, you need to do this hike. In the first part of the hike, you'll get to see Nā Pali Coast on one side and Ke'e beach on the other side. The second part is through a lush green rainforest between the cliffs. Stunning views all over.

The hike to the beach is two miles one way, and there is a stream crossing before you can get to the beach. The beach is more like a cove between cliffs, filled with soft white sand. Pack some lunch, and you can have a picnic on the beach.
The hiking trail can be muddy during rains or after a heavy downpour (so avoid going then). If you get an early start on the hike, you can also hike two more miles inward to see the Hanakapi'ai waterfall. Don't forget to pack a lot of water, the humidity is high. If you're still not convinced, I can assure you there's no other place in Kauaʻi where you get to see such beautiful views for free.

Kayaking in Wailua river

Thanks to the presence of Wailua, river kayaking is a big thing in Kauaʻi. Kayaking felt like getting away from all the crowd and absorbing the serenity in nature. Watching the dense greenery on the hills surrounding the river and listening to birds as you kayak along the water - quite sums up the experience.

After two miles of kayaking, and a quick hike (3/4th mile) inside a forest, you get to the best part - the Secret Falls. Approx. hundred ft in height, these single drop falls are quite beautiful. We dived right in to get a dip. Although the water was cold, the experience of being right under a 100 ft falls is beyond incredible. Packing our lunch also helped, we sat on the rocks in front of these falls and enjoyed our lunch with such a beautiful view. Getting back was the same - 3/4th mile hike and two miles of kayaking. We took a guided tour as recommended - and it cost us approx. 80$ per person.

Sunsets - Kekaha Beach, Sprouting Horn Beach Park, Ke'e Beach

It would surprise me if you are not already aware that sunsets in Hawaii are spectacular. Kauaʻi did not disappoint. Every evening, we would head to the closest beach near the location we were in - and see the sky turn yellow, orange, pink & red.
Sometimes, we could see the sun go down into the ocean and other times, the clouds got in the way. But it didn't matter. Watching the sky turn all these colors in the span of a few minutes is a miracle. I felt blessed to witness them and save them in my memories.

As they say, the best things in life are free. We didn't have to pay anything at any of the beaches. Go on and watch to your heart's content.

Picnic in Waimea Canyon

Waimea Canyon aka "Grand Canyon of the Pacific" makes for a beautiful view. Instead of driving through the view points, we decided to get up-close.
We did the Rim Trail hike (approx. two miles one-way) along the rim of the canyon, and got to see some beautiful views. The hike also passed through some dense greenery and it was surprising to see such a thick forest inside of the "dry" Canyon. Looks can be deceiving!
Carrying our lunch also helped, we stopped at an awesome location and ate our food taking in the gorgeous view of the Canyon. Although much smaller than the Grand Canyon, I'd say Waimea Canyon is as majestic.

Once again, there was no entrance fee to the park, and everything we did here was for free.

What are the best things you did in Kauaʻi?