WOW! Fantastic pics of El Salvador! I lived in La Libertad (Surf City!) for 3 months; surfing and teaching English at the local public school.
I never went into the mountains. Beautiful!
I was there in mid 70's, before the right wing reign of terror had begun. Libertad is one of best surf breaks in all of Mexico / Cent. America. Keep an eye out for White Tips on those calm evenings ... that's when they feed!
If staying on the coast, try the Cazuela de Marizcos (sea food stew) ... best I ever had.
Good BMW community there in El Salvador. Very helpful to travelers.