Most visitors fly to Managua and drive 90 miles to San Juan del Sur (SJDS) and use this as a base for looking at beach property or drive the 30 miles to Granada and use this as a base for colonials, lake and mountain property. Managua itself is also used as a stepping off point for properties further north.
An alternative is to fly to Liberia international airport in Costa Rica and drive across the border into Nicaragua and to SJDS. The distance from the border to SJDS is 28 miles.