Video: The Alamo -- the most famous building in Texas The Alamo might be smaller than a lot of people expect, but it's right in the heart of San Antonio, a couple of blocks from the River Walk. So even if you've forgotten it, you might find yourself there. This video follows visitors inside and out, early and late. The building was born in the 18th century as a Spanish Catholic mission, one of several along the San Antonio River. But by the early 19th century, it had been secularized and converted into a military garrison. Nowadays it's a shrine to Texas liberty, with weapons, flags and other artifacts on display in a hushed exhibition space inside. As the signs inside explain, in 1836, when a bunch of American rebels set out to wrestle Texas away from Mexico, they wound up holed up in the Alamo, vastly outnumbered by Mexican troops outside. The revolutionaries lost the battle - about 200 men died in the fight - but a month later, other revolutionaries (hollering "Remember the Alamo!") effectively won the war by capturing Mexican President Santa Anna at the Battle of San Jacinto. That gave Texas nearly a decade of contested independence before it was annexed to the U.S.