The towering white structure that has been rising alongside the Downtown Connector since late October isn't yet another Midtown skyscraper. It's an enormous tent that will house "Odysseo," the sequel to "Cavalia," which Atlantans flocked to in 2009.

When the original equine and acrobatic extravaganza set up at Atlantic Station then, it was billed as the biggest touring show in the world, with 85 semi trailers hauling a big top spanning 26,264 feet and an 160-foot-wide stage.

"Cavalia" had grown since its launch in 2003. Yet as it toured, founder and artistic director Normand Latourelle was thinking all the while about how a sequel could be even bigger and, he hoped, better.

"Odysseo" launched in the troupe's home city, Montreal, in early October to positive reviews. Latourelle, based on the Atlanta box office-breaking run for a first appearance in a city by "Cavalia," decided that this should be the first stop on its follow-up's world tour.

A big top more than twice as big as the original show's has been taking shape at Spring and 8th streets, causing Interstate motorists to do double-takes. The four masts rising 125 feet and four arches are being covered by 220,000 square feet of white canvas. Created in collaboration with the Italian design firm Canobbio, the tent measures 380 feet long by 175 feet wide (66,500 square feet).

A co-founder of Cirque du Soleil, Latourelle said he wanted a bigger tent to make room for more horses (69, up from 60) and performers (55, up from 40) on a larger and deeper stage (27,000 feet) and also to pull the lobby, concessions and VIP areas under the performance space roof.

While most everything about the sequel is growing, the auditorium will seat 2,290, not a huge jump from the original tour's 2,004. Latourelle said he was more interested making the tent more comfortable and theater like than growing capacity.

The installation, which will continue until around Thanksgiving weekend, when the horses are expected, demands a 250-ton crane and 40 motors.

Because of the tent's larger footprint, "Odysseo" couldn't fit at Atlantic Station. A site in the suburbs might have required less preparation than the Spring Street one, where the grade had to be raised as much as 20 feet in places to make level what had been a sloping surface parking lot.

But Latourelle said he felt it essential to be beside the Downtown Connector. Ticket sales, he said, typically are 10 percent to 15 percent higher in any city when the site is highly visible.

"Odysseo" begins Dec. 7 for a run through Jan. 8 that could be extended. Tickets, $69.50-$134.50 (with discounts for ages 2-17 and 65 and over), are available via 1-866-999-8111, www.cavalia.net.