In the old days, visitors to the Gaslamp were warned all may not be as it appeared. Now, the operators of the newly opened Museum of Illusions (MOI) are keeping that tradition alive.

The 9,000-square-foot museum, which has more than 60 locations around the world — San Diego is the first in California — opened earlier this month. Staffers said attendance has been good — visitors were spotted inside one morning this week after the doors opened at 10 a.m. on 5th Avenue in the location where the old Urban Outfitters used to be.

“We have interactive, freestanding installations,” said general manager Phillip Belmont. “They play with your visual perspective and explore cognitive science. And we have a number of exhibits that take great videos, great photos, and there’s a lot to learn.”

The docents at the Museum of Illusions — and there are a lot of them, BTW; about eight people working at any given time — are especially helpful, and necessary, guiding guests on how to interact with the exhibits or filling in as photographers.

“We have our illusion experts that really are there to serve our guests, help them take photos, help them take videos and explain the science behind our illusions,” Belmont said.

Brain ticklers, optical illusions, 3D holograms and just plain weird stuff will have you and the kids losing count of how many times you say, “Whoa!”

While not every one of the 60 exhibits may have that wow factor, many do, prompting a retracing of steps to replicate the pretzel your mind gets twisted into. Many are interactive, prompting those previously mentioned photo shoots, such as the Ames Room, where an angled floor and mirrors trick perspective into changing the apparent sizes of people and objects; the Walk-In Kaleidoscope; and, our favorite, the Vortex Tunnel, where visitors walk a catwalk through a spinning image that had an NBC 7 photographer unconsciously, unnecesssarily bending his neck to capture a shot.

“I think what makes us most exciting is that you get a chance to really become a part of our illusions, to really be immersed,” Belmont said.

As is the case with many of the other worldwide MOI locations, some of the exhibits in San Diego “pay tribute to the city that we’re in,” as Belmont put it, including a mirrored view of the Colorado House in Old Town that has visitors walking up the side of the building or hanging off of it, and a “surf-themed reverse room” where a “surfer” can pose on a static wave. Altogether, Belmont said, it took about six months to take over the space and open up.

This being the Gaslamp, there ARE night hours: Till 9 during the week and 10 on Fridays and Saturdays.

Potential guests should have no illusions about the cost of a ticket, though: Adults have to pay $35, and kids are $30.