Hubby & I will be visiting our son and his family in Oahu this December. We want to do something fun with the grandgirls ages 3 & 7; any suggestions? Thinking of the zoo and the Polynesian Culture Center but not sure if they're too young for that.

The cultural center is aimed at age 10 and higher as an educational "field trip"... My teens even found it to be repetitive, hot, and somewhat boring, after they experienced other island cultural events...

Consider a whale or Dolphin cruise or some other water event... they also have submarine cruises to view the reefs and little fishies...

There are also countless free Island shows and lessons in Hula for the kiddies... have fun!

Polynesian Cultural Center is great for all ages including the 3 year old. Lots of games, demonstrations, comedy.

Children's Discovery Center is nice for kids.

Byodo-In Temple has a koi (carp pond), black swans, peacocks, a huge gong.

Dole Pineapple has a nice pineapple garden display & a koi pond, both free. It also has a train & a maze.

Bishop Museum is really nice for kids since they recently built an interactive volcano house. Kids can create a volcano & tidal wave.

Sea Life Park is OK, but rather expensive. Not near as good as Sea World.

Honolulu Zoo is nice.

Waikiki Aquarium is good.

They can hike Diamond Head & Manoa Falls.

In Waikiki there is a shopping center with a free walk through aquarium.

Hilton Hawaiian Village has peguins that they can watch for free.

Several free Polynesian shows & demonstrations in or near Waikiki. Check the free brochures for locations & times. One of the best is at the Kuhio stage, nightly. Also on Sundays, there is a keiki hula show at Ala Moana Center. These are kids, some of them are really good.

South Pacific Cultural Center near the Waikiki Shell has free demonstrations (hula, lei making) throughout the day. Also small swap meet there.

Sea turtles at Laniakea Beach on North Shore.

Lots of Oahu info:

http://fodors.com/forums/threadselec...1&tid=34812564

You might also want to consider taking the kids to The Waikiki Aquarium. It is located in Queen Kapiolani Park, on the southern shoreline of the island of Oahu, State of Hawaii. Situated at 2777 Kalakaua Ave. on the Diamond Head (east) end of Waikiki Beach, the Waikiki Aquarium is within easy walking distance of most Waikiki hotels.
Admission daily 9:00 am to 4:30 pm; last guests exit at 5 pm. Admission rates are $9 for visitors; $6 for senior citizens; $4 for Youths (13-17), and persons with disabilities; $2 for Juniors (5-12). Children 4 and under are free. Check the Hawaii Attractions Association Map Guide or the Oahu Drive Guide for special discount coupons.

Here's a link to the Waikiki Aquarium, which my little cousin can't get enough of when she visits. It even has webcams:
http://www.waquarium.org/

And here's a link to a good whale watching cruise. Do it early in your trip, because if you don't see whales, they comp you for the next one so that you DO see them.
www.paradisecruises.com

I think maybe there are two threads going? I posted some of these already on your other one:
paddleboats on Waikiki
free music/hula shows around town
the runner who lights the torches
Waikiki trolly
food court at Ala Moana mall