If you’ve never been to the Tandem Restaurant, the first thing you’re likely to notice is the comfortable and homey atmosphere. Vintage plates are set on wooden tables. A long wooden bar extends almost the entire length of the restaurant, which features an impressive whiskey collection. An outdoor seating area provides open-air dining in good weather.

Tandem, in Lindsay Heights, is one of 170 sites participating in Doors Open Milwaukee this weekend.

This year’s two spotlight neighborhoods are Lindsay Heights and Layton Boulevard West, both in the central city. Doors Open, on Saturday, Sept. 23, and Sunday, Sept. 24, allows guests to visit sites at their leisure, in addition to guided tours.

Ten Doors Open buildings are in Lindsay Heights, while 11 are in Layton Boulevard West. Below are a few highlights:

Tandem Restaurant, 1848 W. Fond Du Lac Ave.

Tandem Restaurant opened in Lindsay Heights 10 months ago. The restaurant specializes in southern-style food that includes burgers, fried chicken, hush puppies, vegetarian options and more, and offers a full-service bar. A vintage tandem bicycle sits above the 100-year-old bar.

Caitlin Cullen, the owner and head chef at Tandem, named the restaurant after a bar two of her uncles owned in Detroit.

“I tailored the menu based on what stakeholders in the community told me,” Cullen said

Cullen visits Fondy’s Farmers Market every Saturday for fresh ingredients. “I love the neighborhood,” Cullen said. “It’s a really tight-knit community.”

The newly renovated building where Tandem operates was once home to the historic Wally Schmidt Tavern. Guests can tour the restaurant on their own on Sunday from 10 a.m. to 5 p.m. or take a guided tour for $10 from 11:30 a.m. to 12: 30 p.m. On Saturday, the restaurant is open for lunch and dinner from 11 a.m. to 10 p.m.

Northside YMCA, 1350 W. North Ave.

The Northside YMCA is located on bustling West North Avenue in Lindsay Heights.

“We are Milwaukee’s best-kept secret,” said Rayven Petersen, operations director at the Northside YMCA. “We want people to know about us and be able to access our resources.”

The Y will be open both Saturday and Sunday from 10 a.m. to 5 p.m. offering free activities and classes including Zumba. All facilities are open to guests, including the 5-foot-deep pool and the workout equipment.

Youth basketball classes are available from 10 a.m. to 12 p.m. both days. Open swim is available to all guests from 2 to 5 p.m.

Petersen said the Y is family-friendly, and a safe place for parents to bring their children.

Escuela Verde is a public charter school that specializes in project-based learning. (Photo by Sue Vliet)

Escuela Verde, 3628 W. Pierce St.

Escuela Verde is a public charter school located in the Layton Boulevard West neighborhood. It is a project-based school, meaning that students work on a specific task for an extended period of time to gain skills and knowledge.

The school, which will be open on Sunday from 10 a.m. to 5 p.m., features a recording booth and a Zen room for activities such as yoga. Escuela Verde also will host a community market on Sunday, featuring local vendors selling different products. There will be a clothing swap at the market as well.

“We want community members to use the building for events and gatherings,” said Zaynab Baalbaki, an advisor at Escuela Verde.

Students provided input on the design of the school, which opened three years ago. Guests are encouraged to look at student projects, including a mural and garden, Baalbaki said. Baalbaki explained the school has an open layout, and there are no traditional classrooms.

Urban Ecology Center, Menomonee Valley, 3700 W. Pierce St.

The Menomonee Valley branch of the Urban Ecology Center opened in September 2012. Since then, the center has gotten community members involved in green and sustainable activities.

The UEC’s Menomonee branch will be open from 10 a.m. to 5 p.m. on Saturday. Attendees are encouraged to walk through the green community center and at 1 p.m. guests can feed the center’s animals, which include snakes, turtles and fish.

“We do not have officially guided tours, but we do have self-guided tours on Saturday,” said Jaime Cana, visitor services specialist at the center’s Menomonee Valley location. Guidebooks are available in both English and Spanish.

Guests also can walk over to Three Bridges Park, which has has two miles of walking and biking trails, river access and 42 community gardens.