The refurbished interior of the “Tower of the Sun” was opened to the public on Monday for the first time since the major artwork by the late Taro Okamoto became a symbol of the Expo ’70 world’s fair in Osaka.

The 70-meter-tall white tower with horn-like arms and three sun faces was built as part of the expo’s theme pavilion in Suita, Osaka Prefecture, but had been kept off limits in principle since the event ended. The prefectural government began refurbishing the interior in 2016.

Long lines of people who had made reservations formed in front of the tower’s entrance at Expo ’70 Commemorative Park in the morning, prompting organizers to open the doors 10 minutes ahead of time.

Visitors enjoyed a projection mapping presentation on the 11-meter-wide tower’s fourth sun, which is underground, with its round face appearing in different colors during the show. The display had been missing since the end of the expo and was reconstructed.

“I’ve seen it in photographs but it was very different when I saw it in person. It was great,” said Ai Takahira, 40, who came from Kyoto Prefecture to see the interior.

The 41-meter-high “Tree of Life,” another Okamoto work inside that depicts the evolution of humans, is now adorned with models of 183 of the 292 creatures found on the original display.

A model of a gorilla has been kept in its original state, with its worn and damaged head revealing the reinforced steel frame inside.

While escalators were available during the expo, they have been renovated into stairs so visitors can take more time to observe the details of the works, the prefecture said.

The tower accepts 80 people every 30 minutes with a maximum of 1,120 people a day. Admission for adults is ¥700 ($6.60), with admission to the park costing ¥250. Reservations are booked for the next four months, park officials said.