Welcome to City Hall! We’re glad you’ve come to fight a parking ticket! Pay taxes! Obtain a death certificate! Get married! Or find a public restroom!

Mayor Martin J. Walsh has stationed greeters — think Walmart or the Apple Store — at the entrance to Boston’s most forbidding building. Look for the bright red fleece vests embroidered with the mayor’s name.

The greeters are college students who help, with a smile. They start with the basics: Constituents may have just walked in from City Hall Plaza, but they are not on the first floor.

“We’re here to say, ‘You’re on the third floor,’ ” said greeter Elizabeth Torres, a 22-year-old from Orlando, cheerfully explaining the odd layout of a structure built into a hill. “That’s a good starting point to be able to give people a little more perspective on where they actually are.”

Go down to the second floor to pay excise taxes. Take the elevators up for nuptials. Get a dog license on eight. Journey to the disability commission way up on nine.

Building permits? Immigration? Housing Court? Wrong government building, but a greeter can show you how to get there.