Scuba-diving Santas, parading penguins, luminous balloons and a maze made of lights — the people of Osaka celebrate the festive season with more than the occasional Christmas tree.

Father Christmas himself drops preparations for his big day with occasional dips in Osaka Aquarium's Pacific Ocean tank, until Dec. 25 of course. His usual animal companions will not be joining in, but if the manta rays and whale shark swimming alongside him still leave visitors wanting more, they can check out the Emperor penguins marching around the forecourt.

In the evening, head to Expo '70 Commemorative Park for the "Illumi Night Benpaku Christmas". Send the children into the "Twinkle Maze," walk down the "Illumi-street," or just watch the balloons mysteriously glowing and swirling around the "Tower of the Sun" sculpture in the center of the park. In keeping with their surroundings, they seem part art-installation, part celebration of simple design and innovation; and their other-worldly swaying is a million miles from the tacky lights that can sometimes define the season.

Osaka Aquarium is a 5-minute-walk from Osaka-ko Station on the JR Chuo Line. Admission is ¥2,000, but the Penguin Parade (until Dec. 29) is open to nonpaying visitors. For more information, call (06) 6576-5501 or visit www.kaiyukan.com/language/eng. Illumi Night takes place at Expo '70 Commemorative Park in Suita, Osaka, on Dec. 23-25 from 4 p.m. till 9 p.m. Admission is ¥250. Take the Osaka Monorail to Bampakukinen-koen Station. For more information, call (06) 6877-3339 or visit www.expo70.or.jp.