Flood-prevention gates in Venice, Italy, were used for the first time to prevent flooding on Oct. 3. After all 78 gates were raised, the tide reached over 4 feet outside of the lagoon in which the city is located, but within the city, which floods when the tide reaches at least 3 feet, the water remained below street level.

The gates, which were first test-operated on July 10, are located at three inlets to the Venice lagoon, where it meets the Adriatic Sea. The system was designed in...

Near the Hardang er fjord in Norway, a hiking bridge across a canyon and above the Vøringsfossen waterfall opened on Aug. 21. The 154-foot-long footbridge includes 99 steps, as one end is at a different elevation than the other. The higher end of the bridge is near the Fossli Hotel (www.fossli-hotel.com). Amenities at the top of the falls, including new paths and lookout points, will be added in 2021.

A 1¼-mile hiking trail to the bottom of the falls, one of Norway’s...

At London’s Postal Museum (15-20 Phoenix Pl., London, England, WC1X 0DA, U.K.; phone +44 300 0300 700, www.postalmuseum.org), visitors can ride on a more-than-100-year-old underground postal railway in replica miniature trains.

A 15-minute ride on the “Mail Rail,” located 70 feet under the former Mt. Pleasant Royal Mail sorting room, is in cramped conditions (carriages are 51 inches from floor to canopy and 31 inches side to side), with portions in total darkness....