You simply can't leave Maui without experiencing Lahaina. A port town, Lahaina is full of things to see and do from shopping to exploring several historical sites.
The main drag is Front Street which you can get to by turning left just before mile marker 20 on Honoapi'ilani Hwy. A few things to see in Lahaina are: the gigantic banyan tree which literally takes up an entire city block, the historic Baldwin House, the old courthouse, and the old prison. Be prepared to search and possibly pay for parking in Lahaina. It is incredibly popular and has the reputation for being crowded. There are plenty of Lahaina activities, shopping, dining and entertainment here. It is home to shows such as Ulalena and the Old Lahaina Luau. There are also some great Lahaina vacation rentals within the port town.
Lahaina is located off of Highway 30 (Honoapiliani Highway) on the western lobe of Maui.