The book Maui Revealed provides more about the history and significance of the area - along with other good tips for visiting Maul.
The paved path starts right from the Parking Lot and Restroom (note there is no drinking water, so be sure to bring some).
The main paved trail leaves the parking lot and heads up toward the viewpoint of the Iao Needle.
To reach the top viewpoint there a couple sets of stairs to climb.
At the top, there is a structure for the scenic viewpoint of Kuka‘emoku ('Iao Needle), an erosional feature which rises about 1200 feet from the valley floor. There are no trails getting any closer to the Needle which was a bit disappointing. However, the view of the Needle from here is very good and even better if the clouds are clearing.
On the way back down, take the trail leading off to the right. This trail leads to the
There is also a botanical garden what has some smaller paths to walk through before returning to the parking lot.
A nice, short, activity for an early morning on Maui. Again, I wouldnt call this a hike, but its a nice walk.
Iao Valley State Park at EveryTrail
Basics:
Area - 'Iao Valley State Monument, Maui, Hawaii
Trails - 'Iao Needle Lookout Trail and Ethnobotanical Loop
Length - 0.6 mile loop - Very Easy Hike (but some steep steps to the lookout point)
Trail - Paved trail
Bikes - None
View - Yes, outstanding on a clear day
Fee - No entrance fee, but parking is $5 per car
Getting there - Follow either Highway 30 or 32 toward Wailuku, then take a left (if on Highway 30) and follow Main Street toward the Mountains. Stay to right upon reaching the intersection with Ioa Valley Road. Follow Ioa Valley Road passing a couple local nurseries. After passing Kepaniwai Park and the Hawai'i Nature Center (currently closed), the road will end up at the parking lot.