San Antonio, Texas from the Riverwalk to the Mission Trail -The jewel of the city is the Riverwalk. After the Alamo, it's the most visited attraction in the State! The chain of missions established along the San Antonio River in the 18th century were the greatest concentration of Catholic missions in North America. The handsome church at Concepción looks essentially as it did more than 200 years ago when it stood at the center of local religious activity. Colorful geometric designs originally covered its surface, but the patterns have long since faded but the beauty remains.