The 5 Strangest Buildings in Connecticut Are Unlike Anything Else Around

Connecticut is renowned for its historic towns and stunning fall foliage, but it’s also home to some genuinely unique and unusual buildings. The strangest buildings in Connecticut range from a bridge covered in giant frogs to a house made entirely of glass to a hilltop castle built by an actor with no architecture degree. Weird architecture in Connecticut isn’t the exception—it’s a recurring theme. Here are five buildings worth going out of your way to see.

The Strangest Buildings You’ll Find in Connecticut

1. Thread City Crossing (“Frog Bridge”), Willimantic

This is exactly what it sounds like: a bridge with giant frogs on it. Built in 2000, the Thread City Crossing sits over the Willimantic River and features four enormous concrete bullfrogs, each perched on top of a giant spool of thread. The spools reference the American Thread Company, which once sat at the heart of this mill town.

The frogs nod to a local legend from 1754, when residents—on edge at the start of a war—mistook the sound of croaking frogs for an attack in the middle of the night. The whole thing is a little absurd and completely charming. Willimantic is about 35–40 minutes east of Hartford, just off I-384.

2. Glass House, New Canaan

The Glass House really is made almost entirely of glass. All four walls are floor-to-ceiling windows, with no curtains, no dividing walls, and almost nowhere to hide. Architect Philip Johnson built it in 1949 and actually lived in it, which might be the strangest part of all.

The only solid section is a brick cylinder in the middle that holds the bathroom and fireplace. The surrounding woods essentially become the walls of the room. It’s one of the most famous examples of modernist architecture in the country, and today it’s a National Trust Historic Site with tours available by advance booking. New Canaan is in Fairfield County, about 20–30 minutes from Stamford.

3. Pirelli Building (Hotel Marcel), New Haven

Most buildings get narrower as they go up. This one gets wider. The Pirelli Building in New Haven was designed in the late 1960s by Marcel Breuer, a Bauhaus-trained architect. Each floor cantilevers outward beyond the one below it, creating a top-heavy silhouette that makes its bold midcentury Brutalist design impossible to miss from the highway.

After decades as an office building—and years sitting vacant—it reopened in 2022 as the boutique Hotel Marcel. It’s one of the only buildings on this list where you can book a room and spend the night. New Haven is easy to reach by train on Amtrak or Metro-North.

4. Heublein Tower, Avon (Talcott Mountain State Park)

Imagine hiking through the woods and suddenly coming across a five-story building sitting alone on top of a mountain. That’s basically what Heublein Tower is. Gilbert Heublein, a businessman who made his money in food and spirits, built it in 1914 as a personal summer getaway. It’s a narrow, slightly tapered structure that looks a bit like a chalet that got lost on its way to the Alps.

Now part of Talcott Mountain State Park in Simsbury, the tower is accessible via a three-mile round-trip hike. The views from the top on a clear day reach all the way to Hartford and, according to reports, as far as five states. The interior opens on weekends during the warmer months, and the tower is about 20 minutes northwest of Hartford.

5. Gillette Castle, East Haddam

William Gillette was a famous actor, best known for playing Sherlock Holmes on stage in the early 1900s. He was not an architect. And yet he spent roughly 20 years designing and building a 24-room stone castle on a cliff above the Connecticut River, finishing it in 1919.

The result is wonderfully odd: stone walls, hand-carved wooden light switches, hidden doors, secret passages, and mirrors rigged so Gillette could watch guests arrive from an upstairs window. When he died, he left the property to the state of Connecticut with a specific request that it not end up in the hands of any "blithering saphead." It’s now a state park open to visitors in East Haddam, about halfway between Hartford and New London.

Photo Opportunities at Connecticut’s Weirdest Buildings

Each of these spots is worth a photo stop, but they’re even better when you build a day around them:

• Gillette Castle: Pair with a Connecticut River ferry ride in East Haddam.
• Hotel Marcel: Walk around Yale’s campus in New Haven.
• Glass House: Make it the centerpiece of an afternoon in Fairfield County.
• Frog Bridge: Best light early in the morning.
• Glass House: Save for golden hour.

Want help mapping out a route? Only In Your State’s itinerary planner can put together a custom day trip around the weirdest, most interesting corners of Connecticut.