Travel Briefs

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) adult, AUD34 senior or AUD28 child. Starting in December 2017, visitors can join a “Group...

On the guided “Colosseum Tour by Night” in Rome, Italy, tour members will visit the tunnels under what was once the Colosseum floor, where gladiators and animals were prepared for their entrances, and see the mechanisms that once operated the Colosseum’s elevators. Afterward, tour members will walk the Via dei Fori Imperiali among the Roman Forum ruins and visit the Piazza del Campidoglio on Capitoline Hill. €79 (near $94). 13 people maximum. Through Eternity Tours (phone, in the US, 800/267-7581, www. througheternity.com).

Passengers on Etihad Airways can bid for the Etihad Select Upgrade (ESU), upgrading to a higher seating class, or, in economy class, for a Neighbor-Free Seat (NSF), bidding on up to three extra neighboring seats (an entire row).After purchasing a seat on an Etihad flight, a passenger may place his bid online at www.etihad.com/en-us/before-you-fly/my-upgrade-options/upgrade-yourself. There are minimum and maximum amounts allowed for bids, though Etihad has not revealed them. When making a bid, a traveler is given a “strength indicator” showing the likelihood of having his bid be...