Alaska is like no other place on earth, and there's no better way to see its pristine waters, snowy mountains, enormous glaciers, and forest-covered islands than on a cruise. Colorful ports of call include the historic village of Ketchikan; Alaska's capital city, Juneau; the gold-rush boomtown of Skagway; and Haines, which boasts the largest concentration of bald eagles in the world. But it is the untamed beauty of Glacier Bay--where humpback whales glide through deep-blue waters--that's truly unforgettable.