Wall in La Llavona

"La llavona" means "the big key". The far end of La Llavona is called "El Prestamo", which means "the loan", and it´s obvious enough why somewhere might be called the loan, if that´s how its development was paid for. I can´t think of any reason to call a hamlet The Big Key. 
The photo shows a wall, window, and hay-loft entrance, garnished with ivy, on an abandoned house in La Llavona.