Aerial view of Banda Neira in Indonesia, with a pentagonal fort built by dutch during the spices war, Maluku, Indonesia

(10:10 a.m. EDT) -- Luxury cruise line Crystal Cruises has revealed details of its 2021 world cruise, a 139-day round-the-world journey on Crystal Serenity that will be one of Crystal's longest. The focus will be "Ancient Dynasties and World Wonders."

Crystal Serenity will visit iconic destinations such as the Panama Canal, Egypt's Valley of the Kings and Australia's Great Barrier Reef, with maiden calls in Townsville, Australia, and Banda Neira and Ambon, Indonesia. The itinerary features overnight stays in 17 cities.

Asia will be a key region, with visits to Japan, Hong Kong, Taiwan, China, South Korea, Singapore and Vietnam. Other destinations include the Caribbean, Hawaii, South Pacific, India, the Middle East and key wine regions in Europe, such as Lisbon and Bordeaux.

Passengers can book the full world cruise or any of nine segments, ranging from 12 to 21 days. Full world cruise passengers can choose from four embarkation/disembarkation date combinations and still receive all the benefits. They can sail from Miami to London, the longest 139-day voyage, departing January 5 and returning May 24, 2019. Or, they can sail from Los Angeles to London (departing January 21) for a 123-day sailing, from Miami to Rome (127 days, ending May 12) or from Los Angeles to Rome (111 days).

Full world cruise perks include a welcome dinner in Miami or Los Angeles, onboard credit up to $2,500 per passenger, private car transfers between the ship and airport, special gifts and invitations to special events onboard and ashore.

Fares start at $46,199 per person for the full cruise. Booking is now open for full world cruise travelers on the 2018 through 2020 world cruises. It opens for past Crystal passengers on September 12 and to the public on September 19.

Curious about Crystal's 2019 and 2020 world cruise itineraries, which are shorter at 85 and 105 nights, respectively? You can find more details in our breakdown of upcoming world cruises.

--By Erica Silverstein, Senior Editor