Engineers are on site at the Rotorua Museum, but there is still no timeframe being put on how long it will remain closed to the public.
The museum was closed as a precaution on Friday after cracks appeared in some parts of the building following last Monday's devastating earthquake.
The museum is a category 1 heritage building and is more than 100 years old.
The cracks were confined to the older, middle portion of the building, which included the entrance, mezzanine and cafe. The newer wings were not affected.
Museum director Stewart Brown said engineers were still in early stages of work to assess the damage.
"We can't yet guess how long that will take and will provide any assistance they [engineers] require. We will let the public know when we know more.
"As part of the council's earthquake-strengthening work programme, engineers were already scheduled to be at the museum this week to begin what's called a 'detailed seismic assessment' to help them understand the level of risk associated with the museum building and develop a plan for strengthening work.
"While the museum is a drawcard for visitors it's only part of the bigger Rotorua package so I don't expect the closure will have a big impact on tourism and at this stage any revenue loss is minimal.
"It's not a priority today," he said.
Mr Brown said the museum had always had cracks, but some became larger after the earthquake.
Destination Rotorua chief executive Michelle Templer said the museum was one of the most photographed buildings in New Zealand, "a true jewel in Rotorua's crown and a great asset for the city".
"However, we do not believe that its temporary closure will decrease the region's allure as a visitor destination.
"While some visitors may not have the opportunity to explore the museum, the team there have been very proactive and have developed a guided walk of the beautiful Government Gardens to ensure our visitors can still enjoy the splendour and architecture of this icon.
"The region is certainly still a safe place for visitors to come and enjoy," she said.
Between 11am and 2pm daily, museum staff are running free tours around the outside of the museum and Government Gardens.
"In the spirit of turning a misfortune into an opportunity, Rotorua Museum is offering free 'outside the walls' guided tours," a statement from the museum said.
"Take in the museum grounds, learn some of the interesting history of battles, buildings and the Government Gardens which were transformed from a wilderness of scrub, hot pools and geysers into an oasis of Victorian charm."
According to a council spokesperson, there are 37 buildings on the council's register which have been deemed earthquake-prone and requiring strengthening work or demolition.
The council doesn't have information about where that work is at for each of these buildings.
As per the council's earthquake-prone building policy, the owners have five, 10 or 15 years in which to complete this work, depending on the level of risk the buildings were assessed to pose to people and/or other property.