At any of four luxury hotels in Playa del Carmen, Mexico, book three nights or more (including Dec. 21, 2012) and get the room for free on the night the Mayan calendar ends. If the world ends, the hotel will repay you double your money.

Rates run $350 per night, double, for a one-bed, one-bath condo to $1,130 for 3-bed/3-bath with views. Contact Condo Hotels Playa del Carmen (866/479-2738). Festivities, Mayan ceremonies, tours and performances are planned.

The 19th-century clipper ship Cutty Sark (King William Walk, Greenwich, London SE10 9HT, U.K.) reopened to visitors on April 25, 2012.

The ship, damaged by a fire (July ’07, pg. 21) during restoration work in May 2007, has been completely restored. £12 ($19) adult or £9.50 senior over 60.

The final steps in the merger of United Airlines and Continental Airlines took place on March 2, 2012, as the last Continental flight landed, the remaining “Continental” signs at airports were removed, its separate ticket counters closed, the “CO” code stopped being printed on tickets, both airlines’ passenger reservation systems were combined, frequent-flyer programs were combined and the old website went dark.