How do you begin to plan a trip to Alaska? Alaska is 2,261 miles across, and twice the size of Texas. It has 24 national parks, more than 3,000 rivers and 3 million lakes, 100 volcanoes, half the world's glaciers and the highest mountain in North America.

Mid-May begins travel season in Alaska, with some cruise ships already running since April. A visit to America's least populated but largest state can be daunting -- there's so much to see and do.

Because so much of the state is undeveloped wilderness, from glaciers and mountains to arctic tundra and remote villages, much of the Land of the Midnight Sun is accessible only by water or air.

Cruise ships only scratch the surface of all that is Alaska, so if you take a cruise, be sure to take advantage of as many excursion opportunities as possible.

Whether you're taking a cruise or traveling to Alaska on your own, here are a few things for your must-do-and-see list.

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