Sit on the natural stone ledge and peer into the pondering pool at the base of the two-story waterfall, and you'll forget you're in a building at Fair Park in Dallas. Best of all, you'll forget the three hot checks that beat your direct deposit to the bank last week, your boss' bullshit, your never-ending "to-do" list and the unsavory state of the world. In the glass-walled conservatory at Texas Discovery Gardens, you'll discover a tranquil, tropical paradise--a cross between Blue Lagoon and Gilligan's Island. Lush, exotic foliage frames the rushing waterfall, including real banana trees with ripening bunches of fruit. The waterfall is the centerpiece among a collection of tropical plants, native and adapted and clearly labeled, cultivated by TDG's crack staff of horticulturists, who are available to answer questions--if you can or want to hear them over the sound of clear, rushing water.