By plane to Puerto Vallarta.
From there either by bus to Lo de Marcos (approx. one to 1.5 hours depending on traffic), or by Uber, or by rental car directly from the airport.
It is about a 20-minute walk from the center of Lo de Marcos to Casa Barbara, and about a 15-minute walk from the house to the nearest beach.
The access to the house is via a somewhat bumpy road, in the rainy season from July to October also a muddy road, which is not tarred or cemented.
