A trestle is a framework of beams that supports something from below, most commonly a bridge or a table. Picture a wooden bridge crossing a deep valley: instead of resting on solid ground, it stands on a series of A-shaped or X-shaped supports rising from the valley floor. Those tower-like supports are trestles.

Railroad trestles were engineering marvels of the 1800s, allowing trains to cross canyons and rivers without needing to build solid embankments. Some wooden railroad trestles stood over 300 feet tall, pieced together from thousands of timber beams. Today, many famous trestle bridges are made of steel and still carry trains across dramatic landscapes.

You'll also encounter trestles in everyday life. A trestle table uses the same basic design: two A-shaped frames support a long tabletop. These tables appear at picnics, craft fairs, and community dinners because they're sturdy, easy to set up, and can be folded away when not needed. The clever geometry of the trestle design, whether holding up a massive bridge or a folding table, distributes weight efficiently down through angled supports.