Israeli researchers say they have discovered the world's longest salt cave. The 10km (6.2 miles) of passages and chambers inside Malham Cave, overlooking the Dead Sea, were mapped out over two years.

Arizona's longest bridge may not be it's most famous, but it is an architectural wonder. Here's what to know about the bridge ...

In fact, the world's longest bridge is a continuous span beam bridge. Almost 24 miles long, the Lake Ponchartrain Causeway consists of two, two-lane sections that run parallel to one another.

they are also some of the longest floating bridges in the world. Three of the bridges span Lake Washington, the other connects to Hood Canal. Residents here probably take them all for granted ...

the newly opened bridge linking the southern Chinese cities of Hong Kong, Macau and Zhuhai is the world's longest sea-crossing structure ever built. Photo: CCTV ...

Stretching more than 55km (34 miles), the Hong Kong–Zhuhai–Macau Bridge spans the Pearl River Delta and is an unparalleled engineering feat. Getty Images From end to end, including its two ...

It's an impressive megaproject, but it's nowhere near as large as the 102-mile-long Danyang-Kunshan Grand Bridge, which is considered the longest in the world. Take a look at some of the most ...