Dates are flexible. This day-by-day plan is provisional until you choose exact travel dates.
Leave Austin around 7:30 AM via I-35 South; the drive to central San Antonio is roughly 1½ hours in light traffic, but allow closer to two hours during the morning commute. Downtown parking is easiest if you go straight to a paid garage near Alamo Plaza or the River Walk, then keep the car parked for the rest of the day. After arrival, start at The Alamo, where the mission church, courtyard, and grounds take about 1–1½ hours. General entry is typically free, but timed admission or special exhibitions may require advance reservations, so check the official schedule before driving down.
Walk across Alamo Plaza to the Menger Bar inside the Menger Hotel for a relaxed, atmospheric lunch or drink amid Victorian-era interiors; budget roughly $20–40 per person and allow about an hour. From there, descend to the San Antonio River Walk and follow the central river-level promenade, crossing its bridges and taking your time with the restaurants, public art, and shaded stretches. A narrated river cruise is a worthwhile add-on if departures are running and tickets are available, but don’t build the day around it without checking same-day schedules. Allow about 1½ hours for the walk, then continue west toward Main Plaza.
At Main Plaza, spend 30–45 minutes admiring the Bexar County Courthouse and the square before visiting San Fernando Cathedral, one of San Antonio’s oldest churches. Check current worship and visitor hours, since access can pause for services; if the evening projection is scheduled, remain for the light show on the plaza, but confirm the current event time in advance rather than assuming it runs every night. Everything in this loop is walkable, though the stone paving and stairs down to the river can be tiring—comfortable shoes and water help. Expect parking to run approximately $15–30 for the day, depending on the garage and duration.
No packing list attached yet.