A German “Enigma” coding machine used in WWII is among more than 1,000 items at the Spy Museum Berlin (Leipziger Platz 9, 10117 Berlin, Germany; phone +49 30 206 203 54, www.deutsches-spionagemuseum.de/en), which opened in September 2015.

On more than 200 high-resolution screens at a dozen stations, visitors learn about the history behind intelligence agents and hear stories of intrigue, including references to Julius Caesar and Oliver Cromwell, though the main focus is...

In post-WWI Ljubljana, Slovenian architect Jože Plecnik designed and built many city landmarks in a neoclassic Greek style. Six works have been nominated for UNESCO World Heritage status, including, in Ljubljana, his promenade and bridges on the Ljubljanica River, the National & University Library, the Church of St. Francis, the Church of St. Michael and the Garden of All Saints in Žale Cemetery.

The architect's home, Plecnik House (Karunova 4-6, 1000 Ljubljana, Slovenia;...

Steam locomotives, royal rail carriages and ephemera are among historical pieces on display at Train World (Princesse Elisabeth 5, 1030 Schaerbeek, Brussels, Belgium; phone +32 02 224 74 98, www.trainworld.be/en), which opened in Brussels’ Schaerbeek Station on Sept. 25, 2015.

The museum is dedicated to Europe’s primary mode of long-distance transportation since 1835, when the continent’s first railway line was completed, connecting Mechelen and Brussels, Belgium....