A sinkhole that swallowed up part of the National Corvette Museum and eight cars proved to be such a popular tourist attraction that the museum wants to keep it, officials said on Thursday.

Attendance at the museum in Bowling Green, Kentucky, is up 59 per cent from last year in the period since shortly after the sinkhole formed in February. That prompted the museum's board to decide on Wednesday to keep part of it open, if possible.

"It never occurred to us this would be a byproduct of this incident," Wendell Strode, museum executive director, said on Thursday.

Geologists believe that the sinkhole, which is 12 metres wide and 18 metres deep, formed due to underground caves, Strode said. The museum has decided to fill in the hole to about nine metres deep.

Corvette Museum-Sinkhole

Tourist Lynn Jones, left, takes a photo of a destroyed 2001 Corvette that was one of several cars that plunged into the sinkhole. (Dylan Lovan/Associated Press)

The eight damaged cars, which are believed to be worth at least $1 million, extracted from the sinkhole have not been repaired and will be on display through the museum's 20th anniversary celebration in late August. Two cars will be returned to the hole, likely including the 2001 Mallett Hammer Z06, Strode said.

After the August anniversary, at least three cars will be restored, Strode said.

The damaged cars range in model years from 1962 to 2009 and include a 1993 ruby red 40th anniversary Corvette and a 2009 ZR1 "Blue Devil" on loan from General Motors. One of the other cars is on loan from General Motors and the other six are owned by the museum. 

Sinkholes are common in the area, located amid a large region of karst bedrock where many of Kentucky's largest and deepest caves run underground.

With files from The Associated Press