Palo Alto Battlefield National Historical Park
No admission feeNational Park Service site on the prairie where U.S. and Mexican forces fought the opening battle of the Mexican-American War in May 1846.

Photo: William L. Farr, CC BY-SA 4.0, via Wikimedia Commons. Cropped and resized.
A Rio Grande Valley state park known for birdwatching, wetland trails, and a wildlife viewing blind.
3301 S. International Blvd. (FM 1015), Weslaco, TX 78596 · Weslaco, TX
This Texas state park in the Lower Rio Grande Valley offers visitors wetlands, ponds, woodlands, and thorn scrub to explore on foot. Its trails total more than five miles, and about two of those miles are wheelchair accessible. The park is a strong destination for birders, with roughly 340 species recorded on site. An accessible blind called the Indigo Blind sits in a tropical zone of native and non-native fruit trees and has a water feature that draws secretive forest birds. Visitors may also spot dragonflies, butterflies, and a few American alligators at Alligator Lake. Cars are not permitted inside the park, so visitors arrive on foot or by bike, and the park offers ranger programs, a junior ranger program for kids, and group facilities.
The closest stops to Estero Llano Grande State Park, ordered by straight-line distance.