10 days on the big island Hawaii

[PatrickH]

There is easily enough to do on the Big Island to keep you busy for 10 days, but Kauai is also amazing. Can't go wrong.

What area are you staying in? It's a big island (no pun intended ) A few favorites:

For photography/hiking:

Volcanoes NP is a must. It's an incredible, alien place. We spent a night in the lodge to break up the drive. Half the rooms have a view of the caldera. I'm not sure if there are any active flows, but the NPS site should provide the latest.
The Hilo side has some nice waterfalls. I particularly like 'Akaka. The waterfall itself is great, but the short walk to it has some impressive flora. It makes for a nice stop if you leave the park to the west.
Waipio Valley also on the west side is also very pretty and a good place to stretch your legs.
On the west/Kona side, the Captain Cook Monument hike leads to an incredible and secluded snorkel spot with the remnants of ancient structures. Go early to beat the tour boats.

R&R

There are two amazing beaches in the Waikaloa area. Hapuna is larger and more accessible. Mauna Kea is less busy, but only because they restrict access. Go early to secure a parking spot.

If you tire of fish and are in Kona, grab a legit NY style pizza and a beer at Patz Pies.