Just a 20-minute combi ride past Santo Domingo [1] is Unión Juárez, a colorful village built on the slope of a mountain. It’s considered the best starting point for an ascent of the Tacaná Volcano [2], though there’s not much reason to come here otherwise. Stroll around the multilevel plaza, enjoy a cup of coffee, and rest up for the challenging hike that lies ahead.
From Tapachula [3], take a Unión y Progreso combi (5a Calle Pte. near 12a Av. Nte.) to Cacahoatán (every 5–10 mins 4 a.m.–10:30 p.m., 1 hr, US$1.50). Once in Cacahoatán, cross the street to the Cordova depot and take a combi to Unión Juárez (every 10 mins, 5 a.m.–8:30 p.m. daily, US$1), about 40 minutes away.
On the return trip, be sure to leave no later than 7 p.m. so that you’re sure to catch the last combi to Tapachula from Cacahoatán at 8 p.m.
Links:
[1] http://www.moon.com/destinations/chiapas/the-pacific-coast/around-tapachula/santo-domingo
[2] http://www.moon.com/destinations/chiapas/the-pacific-coast/around-tapachula/union-juarez/tacana-volcano
[3] http://www.moon.com/destinations/chiapas/the-pacific-coast/tapachula