The last remaining grove of the squat endangered sabal palms in the Rio Grande delta (they are the only palm tree native to the continental United States) is protected for future generations in the 527-acre Sabal Palm Sanctuary (Thurs.-Tues. 7am-5pm), run by the Gorgas Science Foundation with the National Audubon Society and located about five miles southeast of Brownsville. The palms are nice enough, but the reserve is really for the birds: Bird-lovers flock here to catch a glimpse of the rare green jays, as well as the colorful parakeets and hummingbirds that make their homes in the dense junglelike growth. Hundreds of species of butterflies are found here as well.
To reach the reserve from Brownsville, take Southmost Boulevard (Hwy-4) east, then turn right (south) on Sabal Palm Grove Road. The small visitors center (956/541-8034, Thurs.-Tues., $5 adults) has maps and natural history guides to the sanctuary.