Just an hour-and-a-half train ride from the smut-mag bogs, crawdads living in loafers, and waterlogged condoms of Prospect Park Lake and Harlem Meer lies the trout-rich Croton River. The trip there—through the bustle of Grand Central, up the Metro North Harlem line and into the town of Brewster, past the Mexican landscapers on Main Street and into the Croton's brisk waters—is an urban-to-suburban-to-submarine odyssey well worth the $15.50 round-trip. This stretch of the river isn't exactly pristine, but tune out the intercom at the Honda dealership behind you, because there's a placid pool full of spooky browns and rainbows in front of you. You'll need a (free) reservoir permit to fish here, since it's part of NYC's water supply (available at 1250 Broadway, 8th floor