The central plaza in Liberia is a great place to people-watch, especially in the early evenings and on weekends. Grab a seat on one of the many concrete benches, or join the families and young lovers as they leisurely stroll around. If you venture off for a few blocks down Calle Real, you'll see fine examples of the classic Spanish colonial architecture -- adobe buildings with ornate wooden doors, heavy beams, central courtyards, and faded, sagging, red-tile roofs.
While the Catholic church that anchors the central plaza is unspectacular, if you head several blocks east of the plaza, you will come to Iglesia La Ermita de la Agonía, which was built in 1865, and is still in pretty decent shape. The church is open daily for visits from 2:30 to 3:30pm.
It's not much, but you might want to check out the tiny Sabanero Museum (tel. 2665-0135), which has a small collection of photos and exhibits depicting the life and times and tools of the trade of the colonial and post-colonial residents of this horse-and-cattle country. The museum is housed in a small space off the south side of the main church. It's ostensibly open Monday through Saturday from 8am to 5pm, with an hour-long break for lunch; admission is 50¢ (25p). However, because demand is so low, this place is often closed without warning or according to the staff's whims.