Senic Drives, Maui
Any trip to Maui is not complete until you have traveled the road to Hana. This part of Maui is totally different from the touristy side of the island as you travel along the infamous Hana Highway as it hairpins its way through one of Hawai'i's most beautiful tropical rainforest.
The mileage to Hana isn't too bad (the roundtrip from Kahului is 126 miles and 175 miles from Lahaina), but the road is narrow, driving is slow, there are many 1 lane bridges and the scenery is very seductive.
Once you get to Hana, explore the town then continue on (about ten miles) to Ohe'o Gulch. A few miles past Ohe'o Gulch is the burial site of Charles Lindbergh located at the Palapala Ho'Omau Congregational Church.
During our stay at the Renaissance Wailea, we had a small Heron that seem to have made the Mokapu wing his home. He was there 3 of the 5 days that we were there and made the experience all the more enjoyable. Heron's are quite common in Maui, but generally speaking, you have to travel into the marshes and other bodies of inland water to find them. It is not as common to find them on hotel grounds as we did.
One of the things that you must do when you visit Maui is take the trip to Hana. It's a trip back in time and at the same time an ecological wonder as you pass through many ecosystems (coastal, mountains, tropical forest). The driving is slow (it can be an all day trip) but the sights that you see and the people that you meet make this a worth-while adventure.
Once you reach Hana, get out and explore the town (they have a very nice beach), then hop back in the car and continue on past Hana to see more. But please be warned that after about 20 more miles of driving, the road can get very treacherous and car rental companies explicitly forbid you to travel past certain areas.