Akaka and Kahuna falls are beautiful...if you really like waterfalls don't forget about rainbow falls in hilo...a stop by the farmer's market in hilo wouldn't hurt either. Get a touch of the local ways and some really nice exposure to the natural goings on in Hilo and also get some fruit or souvenirs to bring back home. Have fun...just get lost and you'll be able to find your way back but you'll find beautiful little things along the way...have fun!!!