To learn how to photograph the City of Light after dark, visitors to Paris can take the private, 3-hour “Paris Night Photo Tour” with Aperture Tours (25 rue de Cotte, 75012, Paris, France; phone +33 6 17 08 54 45, www.aperturetours.com). Tour members of any skill level will learn night-photography basics, night portraiture, long-exposure techniques and more. 

A tour costs €180 (near $214) for one person and €30 for each additional person up to four. Start...

In Kaunas, Lithuania, a bunker that was built 20 feet underneath a factory during the Soviet era became a private museum in 2014. It holds more than 1,200 items relating to the Cold War, many of them still functioning, including gas masks, radiation detectors, medical equipment and KGB spying devices. Visits to the KGB Atominis Bunkeris (Raudondvario Pl., 164 A, Kaunas, Lithuania; phone +370 8 682 66666, www.atominisbunkeris.lt/en) must be arranged in advance. €6 (near $8).

Holding more than 15,000 native saltwater and freshwater species, the Cairns Aquarium (163 Abbott St., Cairns, Queensland, 4870, Australia; phone +61 7 4044 7300, www.cairnsaquarium.com.au) opened in September. One feature is an acrylic tube in which visitors can sit and watch sharks and rays swim overhead. The tube leads to the Oceanarium, a 528,000-gallon, cylindrical acrylic tank full of sea life and encircled by a walkway. Aquarium hours are 9 a.m.-5:30 p.m. daily. AUD42 (near $33)...