Monterrico is Guatemala's easiest Pacific beach escape from Guatemala City and Antigua Guatemala, but it is not a soft resort strip. The beach is black volcanic sand, the surf breaks hard, and the undertow deserves respect.
The town's appeal is simple: long dark sand, hot afternoons, seafood, small guesthouses, and the mangrove canals behind the settlement. The beach itself is beautiful, but the best day adds a dawn or late-afternoon boat through the mangroves and, in season, a baby turtle release at the local tortugario.
Monterrico is not polished, and that is part of the point. It is a place to slow down, watch the Pacific throw itself at the shore, and remember that Guatemala has a coast as well as volcanoes, highland markets, and Maya ruins.